Solving Systems by Elimination with Multiplication

What is the first step if there are no common coefficients in the given system of equations?

• Add the equations directly.

• Divide one equation by a number.

• Multiply one or both equations by a number to create matching coefficients.

• Subtract the equations directly.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

In Example 1, what is the result of multiplying the top equation by -2?

• 2x + 6y = 12

• -2x - 6y = -12

• 2x - 6y = 12

• -2x + 6y = -12

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

After finding y = 1 in Example 1, which equation is used to find the value of x?

• The unused equation.

• The rearranged equation.

• The equation with the smaller coefficients.

• The equation with the larger coefficients.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

In Example 2, why is the bottom equation multiplied by -3?

• To make the coefficients of y the same.

• To make the coefficients of x the same.

• To simplify the equation.

• To make the signs of the coefficients opposite.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the solution to the system in Example 2?

• (3, 1)

• (2, 5)

• (-1, 7)

• (1, -3)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

In Example 3, why are both equations multiplied by different numbers?

• To make the coefficients of x the same.

• To simplify the equations.

• To make the coefficients of y the same.

• To make the signs of the coefficients opposite.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the solution to the system in Example 3?

• (-2, 5)

• (3, -3)

• (-1, 7)

• (1, 2)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

In Example 4, what is the first step before multiplying the equations?

• Divide one equation by a number.

• Subtract the equations directly.

• Rearrange the equations to standard form.

• Add the equations directly.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

What is the solution to the system in Example 4?

• (-1, 7)

• (1, 2)

• (-2, 5)

• (3, -3)

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

Why is it important to check the solution in the unused equation?

• To rearrange the equations.

• To verify the solution is correct.

• To find the value of y.

• To simplify the equations.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6