Algebraic Solution: Solve using the substitution method

Examples with solutions for Algebraic Solution: Solve using the substitution method

Exercise #1

Solve the following equations:

{2x+y=9x=5 \begin{cases} 2x+y=9 \\ x=5 \end{cases}

Video Solution

Answer

x=5,y=1 x=5,y=-1

Exercise #2

Solve the following equations:

{x+y=18y=13 \begin{cases} x+y=18 \\ y=13 \end{cases}

Video Solution

Answer

x=5,y=13 x=5,y=13

Exercise #3

Find the value of x and and band the substitution method.

{x2y=43x+y=8 \begin{cases} -x-2y=4 \\ 3x+y=8 \end{cases}

Video Solution

Answer

x=4,y=4 x=4,y=-4

Exercise #4

Find the value of x and and band the substitution method.

{x+y=52x3y=15 \begin{cases} x+y=5 \\ 2x-3y=-15 \end{cases}

Video Solution

Answer

x=0,y=5 x=0,y=5

Exercise #5

Find the value of x and and band the substitution method.

{5x+9y=18x+8y=16 \begin{cases} -5x+9y=18 \\ x+8y=16 \end{cases}

Video Solution

Answer

x=0,y=2 x=0,y=2

Exercise #6

Find the value of x and and band the substitution method.

(I)x+3and=12 (I)-x+3and=12

(II)4x+2and=10 (II)4x+2and=10

Video Solution

Answer

x=37,y=297 x=\frac{3}{7},y=\frac{29}{7}

Exercise #7

Choose the correct answer for the following exercise:

{x+y=152x+2y=12 \begin{cases} x+y=15 \\ 2x+2y=12\frac{}{} \end{cases}

Video Solution

Answer

No solution

Exercise #8

Find the value of x and and band the substitution method.

{5x+y=83x2y=11 \begin{cases} -5x+y=8 \\ 3x-2y=11 \end{cases}

Video Solution

Answer

x=277,y=797 x=-\frac{27}{7},y=-\frac{79}{7}

Exercise #9

Find the value of x and and band the substitution method.

{4x+4y=152x+8y=12 \begin{cases} -4x+4y=15 \\ 2x+8y=12 \end{cases}

Video Solution

Answer

x=95,y=3920 x=-\frac{9}{5},y=\frac{39}{20}

Exercise #10

Choose the correct answer for the following exercise:

{2x+3y=144x+6y=28 \begin{cases} -2x+3y=14 \\ -4x+6y=28 \end{cases}

Video Solution

Answer

Infinite solutions

Exercise #11

Find the value of x and and band the substitution method.

{x+4y=53y2x+3y=6 \begin{cases} x+4y=5-3y \\ 2x+3y=6 \end{cases}

Video Solution

Answer

x=2711,y=411 x=\frac{27}{11},y=\frac{4}{11}

Exercise #12

Find the value of x and and band the substitution method.

{8x2y=103x+3y=9 \begin{cases} 8x-2y=10 \\ 3x+3y=9 \end{cases}

Video Solution

Answer

x=85,y=1410 x=\frac{8}{5},y=\frac{14}{10}

Exercise #13

Choose the correct answer for the following exercise:

{8x+5y=1024x+15y=30 \begin{cases} -8x+5y=10 \\ -24x+15y=30 \end{cases}

Video Solution

Answer

Infinite solutions

Exercise #14

Choose the correct answer for the following exercise:

{3x4y=109x12y=15 \begin{cases} 3x-4y=10 \\ 9x-12y=15 \end{cases}

Video Solution

Answer

No solution

Exercise #15

Solve the following equations for x and y using the substitution method:

{2xy2+3y+x5=7yx85y+x6=4 \begin{cases} \frac{2x-y}{2}+\frac{-3y+x}{5}=7 \\ \frac{-y-x}{8}-\frac{5y+x}{6}=4 \end{cases}

Video Solution

Answer

x=1.57,y=4.65 x=1.57,y=-4.65

Exercise #16

Look at the two equations below. Calculate the values of x and y using the substitution method.

{xy2+y+x3=6yx5y+x1=8 \begin{cases}\frac{x-y}{2}+\frac{-y+x}{3}=-6 \\ \frac{-y-x}{5}-\frac{y+x}{1}=8\end{cases}

Video Solution

Answer

x=6.933,y=0.266 x=-6.933,y=0.266

Exercise #17

Choose the correct answer for the following exercise:

{8x+5y=216x+10y=5 \begin{cases} -8x+5y=2 \\ -16x+10y=5 \end{cases}

Video Solution

Answer

No solution

Exercise #18

Solve the following equations for x and y using the substitution method:

{2x3y4+xy5=302y+x83yx4=12 \begin{cases} \frac{2x-3y}{4}+\frac{x-y}{5}=30 \\ \frac{2y+x}{8}-\frac{3y-x}{4}=12 \end{cases}

Video Solution

Answer

x=576,y=456 x=-576,y=-456

Exercise #19

Solve the following equations for x and y using the substitution method.

{3x2y8+xy2=144x+3y52x2y3=20 \begin{cases} \frac{3x-2y}{8}+\frac{x-y}{2}=14 \\ \frac{4x+3y}{5}-\frac{2x-2y}{3}=20 \end{cases}

Video Solution

Answer

x=27.08,y=12.93 x=27.08,y=12.93

Exercise #20

Solve the following equations for x and y using the substitution method.

{x+3y6+5xy3=122x4y102x2y5=15 \begin{cases} \frac{-x+3y}{6}+\frac{5x-y}{3}=12 \\ \frac{2x-4y}{10}-\frac{-2x-2y}{5}=15 \end{cases}

Video Solution

Answer

x=25,y=153 x=25,y=-153