Systems of Equations by Substitution Isolated Variable

Solve for x and y
3x + 2y = 16
7x + y = 19

• (-2,5)

• (-2,-5)

• (2,-5)

• (2,5)

What is the value of the y-coordinate of the solution to the system of equations 
x-2y=1
x+4y=7 

• 1

• -1

• 3

• 4

Which answer has a correct next step for this system? (Read all three answers carefully before selecting one!)

• The variable is already isolated, so we've already solved the system.

• The variable is already isolated for y, so we substitute it in the second equation like this:

  2(6x) + 5y = 32

• The variable is already isolated for y, so we substitute it in the second equation like this:

  2x + 5(6x) = 32

Which answer has a correct next step for this system? (Read all three answers carefully before selecting one!)

• The variable is already isolated, so we've already solved the system.

• The variable is already isolated for y, so we substitute 3x + 5 in the first equation like this:

  3x + 4(3x + 5) = 3

• The variable is already isolated for y, so we substitute 3x + 5 in the second equation like this:

  3(3x + 5) + 4y = 3

What is the solution to this system? (Use the substitution method.) 8x - 2y = 6 y = 3x

• (3, 9)

• (5, 2)

• (2, 3)

• (3, 2)

The first step in solving a system of equations using the SUBSTITUTION METHOD is __________.

(Read all the answers before choosing one.)

• get x by itself

• get y by itself

• get EITHER x or y by itself

• add the equations together

Use the system of equations below to answer the question. After substituting the first equation into the second one and working it out, I got x = 1. What should I do next?

• Fill in 1 for x in y = 6x

• Fill in 1 for y in y = 6x

• Fill in 1 for y in 2x + 5y = 32

Solve the system of equations by using the Substitution Method.

y = 2x - 4

7x - 2y = 5

• (-1, -6)

• (-1, -8)

• (-2, 6)

• (1, -8),

Solve for x and y
2x − 3y = −1
 y = x − 1

• (-2,-3)

• (0,-1)

• (3,4)

• (4,3)

Solve the system of equations.
y = 4x+1
3x + 2y = 13

• (1, 5)

• (5, 1)

• (0.25, 2)

• ∅