Steps Systems of Equations by Substitution

Which option shows the CORRECT substitution for this system?

Which option shows the CORRECT substitution for this system?

Which option shows the CORRECT substitution for this system?

Which option shows the CORRECT substitution for this system?

Put the steps for solving by SUBSTITUTION in order:

• Solve one equation for x or y

• Plug the resulting expression into the other equation

• Solve for the first variable

• Plug that number into the other equation

• Solve for the second variable

In this system x+3y=9 it'll be easiest to start by solving the first equation for x. The result of doing so is x=​9-3y. Fill in the blanks to plug that expression in and solve for y: 4(​9-3y)-2​y =-6 36-​12y-2y=​-6 36-​14y =-6 -14y=​ (a)   y=​ (b)  

• -42

• 3

• 30

• -3

In this system

x+3y=9

4x-2y=-6

it'll be easiest to start by solving the first equation for x.

The result of doing so is x=​

In this system

x+3y=9

4x-2y=-6

it'll be easiest to start by solving the first equation for x.

The result of doing so is x=​9-3y.

Fill in the blanks to plug that expression in and solve for y:

4(​ (a)   )-2​ (b)   =-6

36-​ (c)   y-2y=​ (d)  

36-​ (e)   =-6

• 9-3y

• y

• 12

• -6

• 14y

• x

• 10y

• x+3y

• 24y

In this system

x+3y=9

4x-2y=-6

we have figured out that x=9-3y, and y=3.

Complete the steps to solve for x:

x=9-3(​ (a)   )

x=9-​ (b)  

x=​ (c)  

The solution to the system is (​ (d)   ,​ (e)   ).

• 3

• 9

• 0

• y

• x

• y=3

• 3y

• -9

• 18

Consider the system:

4x+3y=-1

5x+4y=1

Since we now know that x=-7, solve for y:

4(​ (a)   )+3y=-1

​ (b)   +3y=-1

​ (c)   =​ (d)  

y=​ (e)  

• -7

• -28

• 3y

• 27

• 9

• 5

• 7

• -12

• 3

• y