Substitute Values into an Equation and Solve for a Variable

When using the __________ method, you plug in a value into an equation to solve for another variable value.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

x = 3

y = 2x + 5

• (11,3)

• (3,11)

• No Solution

• (3,10)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

solve by substitution: y=3x+14
y=-4x

• y=3

• y=1

• y=2

• y=4

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of linear equations by substitution.

-5x + 3y = 51

y = 10x - 8​

​ ​ ​ (a)   ​ (b)  

• y = -22

• x = -3

• x = 59/25

• y = 15.6

• x = 3

• y = 22

• x = -8

• y = 4

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of linear equations by substitution.

• y = -22

• x = -3

• x = 59/25

• y = 15.6

• x = 3

• y = 22

• x = -8

• y = 4

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of linear equations by substitution.

5x + 2y = 9

x + y = -3

​ ​ ​ (a)   ​ (b)  

• y = -22

• x = -3

• x = 1

• y = -4

• x = 5

• y = -8

• x = -8

• y = 4

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Find the value of k if (-4, -5) is a solution of the equation: 3x - 4y = K

• K = 6

• K = - 6

• K = 8

• K = - 4

Answer explanation

3x - 4y = K Substituting x = - 4 and y = - 5 in the equation, we get, 3(- 4) - 4(- 5) = K - 12 + 20 = K K = 8 Therefore, the value of K = 8

Determine the values of x and y that satisfy the equations: 6x + 2y = 14 and 3x - 5y = 1

• x = 3, y = 4

• x = 2, y = 5

• x = 1, y = 7

• x = 5, y = 2

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Determine the values of x and y that satisfy the equations: 7x - 2y = 5 and 3x + 4y = 11

• x = 4, y = 3

• x = 2, y = 4

• x = 3, y = 2

• x = 5, y = 1

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Find the value of k, if x = - 4, y = - 5 is a solution of the equation: 3x - 4y = K

• K = 6

• K = - 6

• K = 8

• K = - 4

Answer explanation

3x - 4y = K Substituting x = - 4 and y = - 5 in the equation, we get, 3(- 4) - 4(- 5) = K - 12 + 20 = K K = 8 Therefore, the value of K = 8