Substitution of Variable Integers

• (5, 14)

• (8, 11)

• (11, 8)

• (14, 5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What characteristic makes the SUBSTITUTION method more efficient than the other ways to solve systems?

• If one equation already has a variable that is isolated, the expression it is equal to can replace that variable in the other equation. Then you can solve for one of the variable's values.

• Use this method when the 2 equations are in standard form and have exact opposite coefficients so you can add them together to make a zero pair. You can also multiply a number across one equation to make the opposites appear.

• This method works best when both equations are in slope-intercept form and have fractions for their slope and integers for their y-intercepts.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the solution to the system?

• (0, 3)

• (1, -1)

• (-3, 1)

• (1, 3)

Tags

CCSS.8.EE.C.8B

If 2x+3y = 12 and 3x-2y=5 then

• x = 2, y = 3

• x = 2, y = -3

• x = 3, y = 2

• x = 3, y = -2

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What equation will you get when applying substitution?

• -2(x - 2) + 3y = -1

• -2x + 3(x - 2) = -1

• -2x + 3y = x -2

• -2x + 4y = -3

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What equation will you get when applying substitution?

• -2(x - 2) + 3y = -1

• -2x + 3(x - 2) = -1

• -2x + 3y = x -2

• -2x + 4y = -3

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

If I solve the second equation (2x+y=9) for y, what is the result?

• 2x=3y-11

• 2x=9-y

• y=9-2x

• x=18+2y

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

x = 3y

2x + 3y = 36

what would the second equation look like after substitution?

• 3y + 3y = 36

• 23y + 3y = 36

• 2x + 3y = 3y

• 2(3y) + 3y = 36

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