Solving for X with Substitution One Step Equations

Which answer has a correct first step for solving this system without graphing:

• 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 first equation and solve for x

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

• Free sha vaca doo

• The variable is already isolated for y, so we substitute it in the second equation and solve for x

  y = 3(3x + 3y) = 3

Answer explanation

$3x+3y=3$

$y=3x+5$
A variable is already isolated here, so we already have an equivalent expression from the second equation that can be substituted in place of y in the first equation.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

4.4 = x - 5.6

• 10

• 1.2

• 9.2

• 11

Tags

CCSS.6.EE.B.7

What is the first step to solve a system with substitution?

• Substitute the values found from the previous step into one of the original equations and solve for the remaining variable

• Solve the linear system for both its variables

• Solve one equation for one of its variables

• Substitute the expression from the previous step in the other two equations to obtain a linear system in two variables

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

x + 12 = 20

• x = 32

• x = -32

• x = 8

• x = -8

Tags

CCSS.6.EE.B.7

3f - 12 = -3

• 3

• -3

• 11

• 12

Tags

CCSS.7.EE.B.4A

Solve...
2x - 3 = 1 

• 3

• 2

• 1

• -2

Tags

CCSS.7.EE.B.4A

What is the final step to solve a system with substitution?

• Substitute the values found from the previous step into one of the original equations and solve for the remaining variable

• Solve the linear system for both its variables

• Solve one equation for one of its variables

• Solve one equation for one of its variables

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

The first step in solving using the substitution method is __________.

• get x by itself

• get y by itself

• get either variable by itself

• add the equations together

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Which choice shows substitution correctly?

• 2x + 4(3y - 7) = 9

• 2(3y -7) + 4y = 9

What is an important step in solving a system by Substitution?

• Make sure both equations are in standard form.

• Make sure at least one equation is solved for one variable.

• Make sure both equations are the same.

• Make sure both equations can be solved.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6