8.E: Solving Linear Equations (Exercises)
- Page ID
- 5024
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)8.1 - Solve Equations using the Subtraction and Addition Properties of Equality
In the following exercises, determine whether the given number is a solution to the equation.
- x + 16 = 31, x = 15
- w − 8 = 5, w = 3
- −9n = 45, n = 54
- 4a = 72, a = 18
In the following exercises, solve the equation using the Subtraction Property of Equality.
- x + 7 = 19
- y + 2 = −6
- a + \(\dfrac{1}{3} = \dfrac{5}{3}\)
- n + 3.6 = 5.1
In the following exercises, solve the equation using the Addition Property of Equality.
- u − 7 = 10
- x − 9 = −4
- c − \(\dfrac{3}{11} = \dfrac{9}{11}\)
- p − 4.8 = 14
In the following exercises, solve the equation.
- n − 12 = 32
- y + 16 = −9
- f + \(\dfrac{2}{3}\) = 4
- d − 3.9 = 8.2
- y + 8 − 15 = −3
- 7x + 10 − 6x + 3 = 5
- 6(n − 1) − 5n = −14
- 8(3p + 5) − 23(p − 1) = 35
In the following exercises, translate each English sentence into an algebraic equation and then solve it.
- The sum of −6 and m is 25.
- Four less than n is 13.
In the following exercises, translate into an algebraic equation and solve.
- Rochelle’s daughter is 11 years old. Her son is 3 years younger. How old is her son?
- Tan weighs 146 pounds. Minh weighs 15 pounds more than Tan. How much does Minh weigh?
- Peter paid $9.75 to go to the movies, which was $46.25 less than he paid to go to a concert. How much did he pay for the concert?
- Elissa earned $152.84 this week, which was $21.65 more than she earned last week. How much did she earn last week?
8.2 - Solve Equations using the Division and Multiplication Properties of Equality
In the following exercises, solve each equation using the Division Property of Equality.
- 8x = 72
- 13a = −65
- 0.25p = 5.25
- −y = 4
In the following exercises, solve each equation using the Multiplication Property of Equality.
- \(\dfrac{n}{6}\) = 18
- y −10 = 30
- 36 = \(\dfrac{3}{4}\)x
- \(\dfrac{5}{8} u = \dfrac{15}{16}\)
In the following exercises, solve each equation.
- −18m = −72
- \(\dfrac{c}{9}\) = 36
- 0.45x = 6.75
- \(\dfrac{11}{12} = \dfrac{2}{3} y\)
- 5r − 3r + 9r = 35 − 2
- 24x + 8x − 11x = −7−14
8.3 - Solve Equations with Variables and Constants on Both Sides
In the following exercises, solve the equations with constants on both sides.
- 8p + 7 = 47
- 10w − 5 = 65
- 3x + 19 = −47
- 32 = −4 − 9n
In the following exercises, solve the equations with variables on both sides.
- 7y = 6y − 13
- 5a + 21 = 2a
- k = −6k − 35
- 4x − \(\dfrac{3}{8}\) = 3x
In the following exercises, solve the equations with constants and variables on both sides.
- 12x − 9 = 3x + 45
- 5n − 20 = −7n − 80
- 4u + 16 = −19 − u
- \(\dfrac{5}{8} c\) − 4 = \(\dfrac{3}{8} c\) + 4
In the following exercises, solve each linear equation using the general strategy.
- 6(x + 6) = 24
- 9(2p − 5) = 72
- −(s + 4) = 18
- 8 + 3(n − 9) = 17
- 23 − 3(y − 7) = 8
- \(\dfrac{1}{3}\)(6m + 21) = m − 7
- 8(r − 2) = 6(r + 10)
- 5 + 7(2 − 5x) = 2(9x + 1) − (13x − 57)
- 4(3.5y + 0.25) = 365
- 0.25(q − 8) = 0.1(q + 7)
8.4 - Solve Equations with Fraction or Decimal Coefficients
In the following exercises, solve each equation by clearing the fractions.
- \(\dfrac{2}{5} n − \dfrac{1}{10} = \dfrac{7}{10}\)
- \(\dfrac{1}{3} x + \dfrac{1}{5} x = 8\)
- \(\dfrac{3}{4} a − \dfrac{1}{3} = \dfrac{1}{2} a + \dfrac{5}{6}\)
- \(\dfrac{1}{2}\)(k + 3) = \(\dfrac{1}{3}\)(k + 16)
In the following exercises, solve each equation by clearing the decimals.
- 0.8x − 0.3 = 0.7x + 0.2
- 0.36u + 2.55 = 0.41u + 6.8
- 0.6p − 1.9 = 0.78p + 1.7
- 0.10d + 0.05(d − 4) = 2.05
PRACTICE TEST
- Determine whether each number is a solution to the equation. 3x + 5 = 23.
- 6
- \(\dfrac{23}{5}\)
In the following exercises, solve each equation.
- n − 18 = 31
- 9c = 144
- 4y − 8 = 16
- −8x − 15 + 9x − 1 = −21
- −15a = 120
- \(\dfrac{2}{3}\)x = 6
- x + 3.8 = 8.2
- 10y = −5y + 60
- 8n + 2 = 6n + 12
- 9m − 2 − 4m + m = 42 − 8
- −5(2x + 1) = 45
- −(d + 9) = 23
- \(\dfrac{1}{3}\)(6m + 21) = m − 7
- 2(6x + 5) − 8 = −22
- 8(3a + 5) − 7(4a − 3) = 20 − 3a
- \(\dfrac{1}{4} p + \dfrac{1}{3} = \dfrac{1}{2}\)
- 0.1d + 0.25(d + 8) = 4.1
- Translate and solve: The difference of twice x and 4 is 16.
- Samuel paid $25.82 for gas this week, which was $3.47 less than he paid last week. How much did he pay last week?
Contributors and Attributions
Lynn Marecek (Santa Ana College) and MaryAnne Anthony-Smith (Formerly of Santa Ana College). This content is licensed under Creative Commons Attribution License v4.0 "Download for free at http://cnx.org/contents/fd53eae1-fa2...49835c3c@5.191."