Systems of Equations Elimination Add

What is the solution to the system?

• (0, 3)

• (1, -1)

• (-3, 1)

• (1, 3)

Answer explanation

The lines intersect at (1,3) so that is the solution.

Tags

CCSS.8.EE.C.8A

What is the first step in solving a system of equations by elimination?

• Rewrite the equations so the variables are all on the same side and line up the like terms.

• Get both equations in slope-intercept form.

• Get both equations equal to zero.

• Put the x terms first.

Answer explanation

We need all of the variables on the same side so that we can eventually add the left side of both equations together and add the right side of both equations together.

If the variables aren't on the same side of the equal-sign, then we can't combine like terms.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

7x - y = 10

-7x + y = -14

• No Solution

• (4, 1)

• Infinitely Many Solutions

• (2, -4)

Answer explanation

7x - y = 10

-7x + y = -14

All of the like terms have opposite coefficients, so both variables will be eliminated when we add the equations together. We cannot eliminate one without the other.

We are left with:

0=-4

This is a contradiction (false), so there is NO SOLUTION.

Tags

CCSS.8.EE.C.8B

Which of the following is NOT a method to solve systems?

• Elimination

• Distribution

• Substitution

• Graphing

Answer explanation

You may at times need to use distribution to help you solve a system of equations, but it is not the overall method.

Distribution is a property that helps us to simplify equations and expressions.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Will the solution (-3, -7) make the following system of equations a true statement?

• YES

• NO

Answer explanation

Now, our equations will look like this
-4x - 6y = -24
4x - 7y = - 54

Let's combine (add) these 2 equations to ELIMINATE the x variable. What would our combined equations be?

• -1y = 30

• 13y = -30

• -1y = -78

• -13y = -78

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

2x + 9y = -7

6x - 3y = 9

• (-1, -1)

• (2,-1)

• (1,1)

• (1,-1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve by elimination
-2x + 6y = 16
-4x - 3y = 2

• (2,2)

• (-2, -2)

• (-2,2)

• (2,1)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Solve for x and y
3x + 2y = 16
7x + y = 19

• (-2,5)

• (-2,-5)

• (2,-5)

• (2,5)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the solution to the system of equations below?

• (3, 1)

• (4, 6)

• (5, 5)

• (6, 4)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6