Introduction to Substitution Method

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

• get x by itself

• get y by itself

• get either variable by itself in one equation

• add the equations together

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by substitution method:

y = -6

-3x - 6y = 24

• (6, 6)

• (6, -6)

• (4, -6)

• (-6, 4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the solution to the system of equations?

y = 3x - 8

y = 4 - x

• (3, 1)

• (1, 3)

• (-3, 1)

• (3, -1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of equations using substitution:

-4x + 4y = 8

y = -2x - 10

• (-4, -2)

• (12, -34)

• (4, -18)

• (-2, -6)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system by substitution method:

x + 6y = 17

x - 3y = 8

• (5, 2)

• (11, 1)

• (1, 11)

• no solution

Tags

CCSS.8.EE.C.8B

What is the solution?

3x + 5y = 13

2x + y = 4

• Infinite solutions

• (2,1)

• (1,2)

• No solution

Tags

CCSS.8.EE.C.8B