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2.2 Linear Equations in One Variable

Solving first-degree and rational equations algebraically, then finding a line's equation and testing whether two lines are parallel or perpendicular.

Algebra and Trigonometry 2e, 2.2 Linear Equations in One Variable

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53 exercises

2.2 Exercise 11

Solve linear equations using a general strategy.

2(w+5)+1=10+4w+22 \left(w + 5\right) + 1 = 10 + 4 w + 2

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Solving an Equation in One Variable

Solve the following equation: 2x+7=19. 2 x + 7 = 19.

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2.2 Exercise 21

Solve the linear equation in one variable: 2x+1=−9. 2 x + 1 = −9.

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Solving an Equation Algebraically When the Variable Appears on Both Sides

Solve the following equation: 4( x−3 )+12=15−5( x+6 ). 4 \left(x −3\right) + 12 = 15 −5 \left(x + 6\right) .

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2.2 Exercise 23

Solve the equation in one variable: −2( 3x−1 )+x=14−x. −2 \left(3 x - 1\right) + x = 14 - x .

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Solving a Rational Equation

Solve the rational equation: 7 2x − 5 3x = 22 3 . \frac{7}{2 x} - \frac{5}{3 x} = \frac{22}{3} .

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Solving a Rational Equation without Factoring

Solve the following rational equation:

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2.2 Exercise 26

Solve the rational equation: 2 3x = 1 4 − 1 6x . \frac{2}{3 x} = \frac{1}{4} - \frac{1}{6 x} .

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Solving a Rational Equation by Factoring the Denominator

Solve the following rational equation: 1 x = 1 10 − 3 4x . \frac{1}{x} = \frac{1}{10} - \frac{3}{4 x} .

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2.2 Exercise 28

Solve the rational equation: − 5 2x + 3 4x =− 7 4 . - \frac{5}{2 x} + \frac{3}{4 x} = - \frac{7}{4} .

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Solving Rational Equations with a Binomial in the Denominator

Solve the following rational equations and state the excluded values:

  1. ⓐ 3 x−6 = 5 x \frac{3}{x - 6} = \frac{5}{x}
  2. ⓑ x x−3 = 5 x−3 − 1 2 \frac{x}{x - 3} = \frac{5}{x - 3} - \frac{1}{2}
  3. ⓒ x x−2 = 5 x−2 − 1 2 \frac{x}{x - 2} = \frac{5}{x - 2} - \frac{1}{2}
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2.2 Exercise 30

Solve −3 2x+1 = 4 3x+1 . \frac{- 3}{2 x + 1} = \frac{4}{3 x + 1} . State the excluded values.

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Solving a Rational Equation with Factored Denominators and Stating Excluded Values

Solve the rational equation after factoring the denominators: 2 x+1 − 1 x−1 = 2x x 2 −1 . \frac{2}{x + 1} - \frac{1}{x - 1} = \frac{2 x}{x^{2} - 1} . State the excluded values.

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2.2 Exercise 32

Solve the rational equation: 2 x−2 + 1 x+1 = 1 x 2 −x−2 . \frac{2}{x - 2} + \frac{1}{x + 1} = \frac{1}{x^{2} - x - 2} .

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Finding the Slope of a Line Given Two Points

Find the slope of a line that passes through the points ( 2,−1 ) \left(2 , −1\right) and ( −5,3 ). \left(−5 , 3\right) .

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2.2 Exercise 34

Find the slope of the line that passes through the points ( −2,6 ) \left(−2 , 6\right) and ( 1,4 ). \left(1 , 4\right) .

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Identifying the Slope and y- intercept of a Line Given an Equation

Identify the slope and y-intercept, given the equation y=− 3 4 x−4. y = - \frac{3}{4} x - 4.

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Finding the Equation of a Line Given the Slope and One Point

Write the equation of the line with slope m=−3 m = −3 and passing through the point ( 4,8 ). \left(4 , 8\right) . Write the final equation in slope-intercept form.

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2.2 Exercise 37

Given m=4, m = 4 , find the equation of the line in slope-intercept form passing through the point ( 2,5 ). \left(2 , 5\right) .

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Finding the Equation of a Line Passing Through Two Given Points

Find the equation of the line passing through the points ( 3,4 ) \left(3 , 4\right) and ( 0,−3 ). \left(0 , −3\right) . Write the final equation in slope-intercept form.

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Finding the Equation of a Line and Writing It in Standard Form

Find the equation of the line with m=−6 m = −6 and passing through the point ( 1 4 ,−2 ). \left(\frac{1}{4} , −2\right) . Write the equation in standard form.

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2.2 Exercise 40

Find the equation of the line in standard form with slope m=− 1 3 m = - \frac{1}{3} and passing through the point ( 1, 1 3 ). \left(1 , \frac{1}{3}\right) .

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Finding the Equation of a Line Passing Through the Given Points

Find the equation of the line passing through the given points: ( 1,−3 ) \left(1 , −3\right) and ( 1,4 ). \left(1 , 4\right) .

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2.2 Exercise 42

Find the equation of the line passing through ( −5,2 ) \left(−5 , 2\right) and ( 2,2 ). \left(2 , 2\right) .

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2.2 Exercise 46

Find the equation of the line parallel to 5x=7+y 5 x = 7 + y and passing through the point ( −1,−2 ). \left(−1 , −2\right) .

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Finding the Equation of a Line Perpendicular to a Given Line Passing Through a Given Point

Find the equation of the line perpendicular to 5x−3y+4=05 x - 3 y + 4 = 0 and passing through the point ( −4,1 ). \left(- 4 , 1\right) .

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2.2 Exercise 48

What does it mean when we say that two lines are parallel?

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2.2 Exercise 50

How do we recognize when an equation, for example y=4x+3, y = 4 x + 3 , will be a straight line (linear) when graphed?

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2.2 Exercise 52

When solving the following equation:

2 x−5 = 4 x+1 \frac{2}{x - 5} = \frac{4}{x + 1}

explain why we must exclude x=5 x = 5 and x=−1 x = −1 as possible solutions from the solution set.

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2.2 Exercise 54

Solve the equation for x. x .

4x−3=5 4 x - 3 = 5

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2.2 Exercise 56

Solve the equation for x. x .

12−5(x+3)=2x−5 12 - 5 \left(x + 3\right) = 2 x - 5

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2.2 Exercise 58

Solve the equation for x. x .

x 3 − 3 4 = 2x+3 12 \frac{x}{3} - \frac{3}{4} = \frac{2 x + 3}{12}

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2.2 Exercise 60

Solve the equation for x. x .

3(2x−1)+x=5x+3 3 \left(2 x - 1\right) + x = 5 x + 3

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2.2 Exercise 62

Solve the equation for x. x .

x+2 4 − x−1 3 =2 \frac{x + 2}{4} - \frac{x - 1}{3} = 2

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2.2 Exercise 64

Solve each rational equation for x. x . State all x-values that are excluded from the solution set.

2− 3 x+4 = x+2 x+4 2 - \frac{3}{x + 4} = \frac{x + 2}{x + 4}

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2.2 Exercise 66

Solve each rational equation for x. x . State all x-values that are excluded from the solution set.

3x x−1 +2= 3 x−1 \frac{3 x}{x - 1} + 2 = \frac{3}{x - 1}

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2.2 Exercise 68

Solve each rational equation for x. x . State all x-values that are excluded from the solution set.

1 x = 1 5 + 3 2x \frac{1}{x} = \frac{1}{5} + \frac{3}{2 x}

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2.2 Exercise 70

Find the equation of the line using the point-slope formula. Write all the final equations using the slope-intercept form.

( 1,2 ) \left(1 , 2\right) with a slope of − 4 5 - \frac{4}{5}

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2.2 Exercise 72

Find the equation of the line using the point-slope formula. Write all the final equations using the slope-intercept form.

y-intercept is 2, and ( 4,−1 ) \left(4 , −1\right)

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2.2 Exercise 74

Find the equation of the line using the point-slope formula. Write all the final equations using the slope-intercept form.

( 1,3 ) and  ( 5,5 ) \left(1 , 3\right) \textrm{ }\text{and}\textrm{ }\textrm{ } \left(5 , 5\right)

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2.2 Exercise 76

Find the equation of the line using the point-slope formula. Write all the final equations using the slope-intercept form.

perpendicular to 3y=x−4 \text{3} y = x - 4 and passes through the point ( −2,1 ) \left(−2 , 1\right) .

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2.2 Exercise 78

Find the equation of the line using the given information.

( 1,7 ) \left(1 , 7\right) and ( 3,7 ) \left(3 , 7\right)

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2.2 Exercise 80

Find the equation of the line using the given information.

The slope equals zero and it passes through the point ( 1,−4 ). \left(1 , −4\right) .

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2.2 Exercise 82

Find the equation of the line using the given information.

(–1,3)\left(–1 , 3\right) and (4,–5)\left(4 , –5\right)

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2.2 Exercise 88

Find the slope of the line that passes through the given points.

( −3,2 ) \left(−3 , 2\right) and ( 4,−7 ) \left(4 , −7\right)

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2.2 Exercise 90

Find the slope of the line that passes through the given points.

( −1,−2 ) \left(−1 , −2\right) and ( 3,4 ) \left(3 , 4\right)

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2.2 Exercise 92

Find the slope of the lines that pass through each pair of points and determine whether the lines are parallel or perpendicular.

( −1,3 ) and  ( 5,1 ) ( −2,3 ) and  ( 0,9 ) \begin{matrix}\left(−1 , 3\right) \textrm{ }\text{and}\textrm{ }\textrm{ } \left(5 , 1\right) \\ \left(−2 , 3\right) \textrm{ }\text{and}\textrm{ }\textrm{ } \left(0 , 9\right)\end{matrix}

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2.2 Exercise 94

Express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values.

0.537x−2.19y=100 0.537 x - 2.19 y = 100

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2.2 Exercise 96

Express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values.

200−30y x =70 \frac{200 - 30 y}{x} = 70

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2.2 Exercise 98

Starting with the standard form of an equation Ax+By=CA x + B y = C solve this expression for yy in terms of A,B,CA , B , C and xx. Then put the expression in slope-intercept form.

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2.2 Exercise 100

Given that the following coordinates are the vertices of a rectangle, prove that this truly is a rectangle by showing the slopes of the sides that meet are perpendicular.

(–1,1),(2,0),(3,3)\left(– 1 , 1\right) , \left(2 , 0\right) , \left(3 , 3\right) and (0,4)\left(0 , 4\right)

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2.2 Exercise 104

Use this scenario: The cost of renting a car is $45/wk plus $0.25/mi traveled during that week. An equation to represent the cost would be y=45+.25x, y = 45 + .25 x , where x x is the number of miles traveled.

What is your cost if you travel 50 mi?

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2.2 Exercise 106

Use this scenario: The cost of renting a car is $45/wk plus $0.25/mi traveled during that week. An equation to represent the cost would be y=45+.25x, y = 45 + .25 x , where x x is the number of miles traveled.

Suppose you have a maximum of $100 to spend for the car rental. What would be the maximum number of miles you could travel?

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Adapted from College Algebra © 2021 Rice University. Licensed under CC BY 4.0. Sources: College Algebra 2e, Algebra and Trigonometry 2e, Precalculus 2e, College Algebra with Corequisite Support 2e. Imported at revision 4922e46.