Graphing and Solving by Substitution

x - 3y = -13
4x + 2y = 4

• (1, 4)

• (-1, -4)

• (-1, 4)

• (1, -4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the following System of Equations using the Substitution Method:

• (3, 6)

• (9, 18)

• (2, 4)

• (9, 32)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

If a system of equations has no solution, what does the graph look like?

• intersecting lines

• parallel lines

• same lines

Tags

CCSS.8.EE.C.8A

If the solution is infinitely many the lines will ________?

• intersect at exactly one point

• be parallel

• overlap each other

• never exist

Tags

CCSS.8.EE.C.8A

Which variable should you isolate first in the system?

• The x in the first equation

• The y in the first equation

• The y in the second equation

• The x in the second equation

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the correct first step in solving this system by substitution?

• -7(2y+11) - 2y = -13

• -7x -2(2y +11) = -13

• 2y+11-2y = -13

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve with substitution

x = -3y - 8

x - 2y = -3

• (5, -1)

• (-5, 1)

• (-5,-1)

• (1,-5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system by substitution

3x - y = 4

x + 2y = 6

• (-2, 2)

• (2, -2)

• (2, 2)

• (-2, -2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the best method to use?

y = −3x + 5

y = x -1

• Graphing, because they are both in slope-intercept form

• Substitution because a variable is isolated (solved for)

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