First Step Systems Substitution

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 variable should you isolate first in the system?

3x + 2y = 10

x - 5y = 18

• 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

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 do you use?

x = 6y − 11

−2x − 3y = −7

• 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

These two lines intersect at _____

• (4, -2)

• (4, 2)

• (-2, 4) 

• No solution

Tags

CCSS.8.EE.C.8B

How many solutions does the graph have?

• One solution

• No solution

• Infinite solutions

Tags

CCSS.8.EE.C.8B

Which is the best method to use?

• Graphing

• Substitution because a variable is isolated.

• Elimination because both equations are in standard form.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve the system of equations.

• (-34, -17)

• (8, 4)

• (10, 20)

• No solution

• Infinite solutions

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the first 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 in slope-intercept form.

• Make sure both equations can be solved.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the solution to the following system?

^{x - y = 6}

^{x = 11}

• (11, 5)

• (55, 5)

• (11, 11)

• (5, 55)

Tags

CCSS.HSA.REI.C.9