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4.7 Graphs of Linear Inequalities

Shading the half-plane of solutions, choosing a dashed or solid boundary line, and using a test point to decide which side gets shaded.

Elementary Algebra 2e, 4.7 Graphs of Linear Inequalities

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45 exercises

4.7 Exercise 1

Before you get started, take this readiness quiz.

Solve: 4x+3>234 x + 3 > 23.
If you missed this problem, review the reference.

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4.7 Exercise 2

Translate from algebra to English: x<5x < 5.
If you missed this problem, review the reference.

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4.7 Exercise 3

Evaluate 3x−2y3 x - 2 y when x=1x = 1, y=−2y = −2.
If you missed this problem, review the reference.

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4.7 Exercise 5

Determine whether each ordered pair is a solution to the inequality y>x−3y > x - 3:

ⓐ (0,0)\left(0 , 0\right) ⓑ (4,9)\left(4 , 9\right) ⓒ (−2,1)\left(−2 , 1\right) ⓓ (−5,−3)\left(−5 , −3\right) ⓔ (5,1)\left(5 , 1\right)

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4.7 Exercise 6

Determine whether each ordered pair is a solution to the inequality y<x+1y < x + 1:

ⓐ (0,0)\left(0 , 0\right) ⓑ (8,6)\left(8 , 6\right) ⓒ (−2,−1)\left(−2 , −1\right) ⓓ (3,4)\left(3 , 4\right) ⓔ (−1,−4)\left(−1 , −4\right)

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4.7 Exercise 26

Determine whether each ordered pair is a solution to the given inequality.

Determine whether each ordered pair is a solution to the inequality y>x−3y > x - 3:

  1. ⓐ (0,0)\left(0 , 0\right)
  2. ⓑ (2,1)\left(2 , 1\right)
  3. ⓒ (−1,−5)\left(−1 , −5\right)
  4. ⓓ (−6,−3)\left(−6 , −3\right)
  5. ⓔ (1,0)\left(1 , 0\right)
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4.7 Exercise 28

Determine whether each ordered pair is a solution to the given inequality.

Determine whether each ordered pair is a solution to the inequality y<x+5y < x + 5:

  1. ⓐ (−3,0)\left(−3 , 0\right)
  2. ⓑ (1,6)\left(1 , 6\right)
  3. ⓒ (−6,−2)\left(−6 , −2\right)
  4. ⓓ (0,1)\left(0 , 1\right)
  5. ⓔ (5,−4)\left(5 , −4\right)
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4.7 Exercise 30

Determine whether each ordered pair is a solution to the given inequality.

Determine whether each ordered pair is a solution to the inequality x+y>2x + y > 2:

  1. ⓐ (1,1)\left(1 , 1\right)
  2. ⓑ (4,−3)\left(4 , −3\right)
  3. ⓒ (0,0)\left(0 , 0\right)
  4. ⓓ (−8,12)\left(−8 , 12\right)
  5. ⓔ (3,0)\left(3 , 0\right)
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4.7 Exercise 84

Which ordered pairs are solutions to the given equations?

y=6x−2y = 6 x - 2

  1. ⓐ (1,4)\left(1 , 4\right)
  2. ⓑ (13,0)\left(\frac{1}{3} , 0\right)
  3. ⓒ (6,−2)\left(6 , −2\right)
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4.7 Exercise 86

Complete the table to find solutions to each linear equation.

y=−12x+3y = - \frac{1}{2} x + 3

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4.7 Exercise 88

Complete the table to find solutions to each linear equation.

3x+2y=63 x + 2 y = 6

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4.7 Exercise 90

Find three solutions to each linear equation.

x+y=−4x + y = −4

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4.7 Exercise 92

Find three solutions to each linear equation.

y=−x−1y = − x - 1

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4.7 Exercise 108

Find the intercepts of each equation.

x−y=−1x - y = −1

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4.7 Exercise 110

Find the intercepts of each equation.

2x+3y=122 x + 3 y = 12

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4.7 Exercise 112

Find the intercepts of each equation.

y=3xy = 3 x

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4.7 Exercise 132

Find the slope of each line.

x=5x = 5

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4.7 Exercise 134

Find the slope of each line.

y=−1y = −1

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4.7 Exercise 136

Use the slope formula to find the slope of the line between each pair of points.

(3,5),(4,−1)\left(3 , 5\right) , \left(4 , −1\right)

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4.7 Exercise 138

Use the slope formula to find the slope of the line between each pair of points.

(2,1),(4,6)\left(2 , 1\right) , \left(4 , 6\right)

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4.7 Exercise 144

Solve these slope applications.

A mountain road rises 50 feet for a 500-foot run. What is its slope?

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4.7 Exercise 148

Identify the slope and y-intercept of each line.

y=53x−6y = \frac{5}{3} x - 6

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4.7 Exercise 150

Identify the slope and y-intercept of each line.

4x−5y=84 x - 5 y = 8

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4.7 Exercise 156

Determine the most convenient method to graph each line.

y=−3y = −3

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4.7 Exercise 158

Determine the most convenient method to graph each line.

x−y=2x - y = 2

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4.7 Exercise 160

Determine the most convenient method to graph each line.

y=34x−1y = \frac{3}{4} x - 1

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4.7 Exercise 164

Use slopes and y-intercepts to determine if the lines are parallel.

2x−y=8;x−2y=42 x - y = 8 ; x - 2 y = 4

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4.7 Exercise 166

Use slopes and y-intercepts to determine if the lines are perpendicular.

3x−2y=5;2x+3y=63 x - 2 y = 5 ; 2 x + 3 y = 6

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4.7 Exercise 168

Find the equation of a line with given slope and y-intercept. Write the equation in slope–intercept form.

slope −5−5 and y-intercepty -\text{intercept} (0,−3)\left(0 , −3\right)

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4.7 Exercise 170

Find the equation of a line with given slope and y-intercept. Write the equation in slope–intercept form.

slope −2−2 and y-intercepty -\text{intercept} (0,0)\left(0 , 0\right)

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4.7 Exercise 176

Find the equation of a line with given slope and containing the given point. Write the equation in slope–intercept form.

m=35m = \frac{3}{5}, point (10,6)\left(10 , 6\right)

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4.7 Exercise 178

Find the equation of a line with given slope and containing the given point. Write the equation in slope–intercept form.

m=−2m = −2, point (−1,−3)\left(−1 , −3\right)

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4.7 Exercise 180

Find the equation of a line containing the given points. Write the equation in slope–intercept form.

(7,1)\left(7 , 1\right) and (5,0)\left(5 , 0\right)

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4.7 Exercise 182

Find the equation of a line containing the given points. Write the equation in slope–intercept form.

(5,2)\left(5 , 2\right) and (−1,2)\left(−1 , 2\right)

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4.7 Exercise 184

Find an equation of a line parallel to the given line and contains the given point. Write the equation in slope–intercept form.

line 2x+5y=−102 x + 5 y = −10, point (10,4)\left(10 , 4\right)

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4.7 Exercise 186

Find an equation of a line parallel to the given line and contains the given point. Write the equation in slope–intercept form.

line y=−5y = −5, point (−4,3)\left(−4 , 3\right)

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4.7 Exercise 188

Find an equation of a line perpendicular to the given line and contains the given point. Write the equation in slope–intercept form.

line 2x−3y=92 x - 3 y = 9, point (−4,0)\left(−4 , 0\right)

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4.7 Exercise 190

Find an equation of a line perpendicular to the given line and contains the given point. Write the equation in slope–intercept form.

line x=−5x = −5 point (2,1)\left(2 , 1\right)

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4.7 Exercise 192

Determine whether each ordered pair is a solution to the given inequality.

Determine whether each ordered pair is a solution to the inequality x+y>4x + y > 4:

  1. ⓐ (6,1)\left(6 , 1\right)
  2. ⓑ (−3,6)\left(−3 , 6\right)
  3. ⓒ (3,2)\left(3 , 2\right)
  4. ⓓ (−5,10)\left(−5 , 10\right)
  5. ⓔ (0,0)\left(0 , 0\right)
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4.7 Exercise 204

Which of the given ordered pairs are solutions to the equation 3x−y=63 x - y = 6?

  1. ⓐ (3,3)\left(3 , 3\right)
  2. ⓑ (2,0)\left(2 , 0\right)
  3. ⓒ (4,−6)\left(4 , −6\right)
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4.7 Exercise 206

Find the x- and y-intercepts of the equation 4x−3y=124 x - 3 y = 12.

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4.7 Exercise 210

Find the slope of each line shown.

Find the slope of the line between the points (5,2)\left(5 , 2\right) and (−1,−4)\left(−1 , −4\right).

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4.7 Exercise 218

Find the equation of each line. Write the equation in slope–intercept form.

slope −34- \frac{3}{4} and y-intercept (0,−2)\left(0 , −2\right)

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4.7 Exercise 220

Find the equation of each line. Write the equation in slope–intercept form.

containing (10,1)\left(10 , 1\right) and (6,−1)\left(6 , −1\right)

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4.7 Exercise 222

Find the equation of each line. Write the equation in slope–intercept form.

perpendicular to the line y=54x+2y = \frac{5}{4} x + 2, containing the point (−10,3)\left(−10 , 3\right)

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Adapted from Elementary Algebra 2e © 2020 Rice University. Licensed under CC BY 4.0. Source: Elementary Algebra 2e. Imported at revision 77a933c.