Solving Systems of Equations 1/25 Review

what is the resulting combined equation for the system below?

9x + y = 12

-9x + y = 6

• -18x = 18

• y = 18

• 2y= 18

• 18x + 2y = 18

What is the solution?

• (1, -1)
• (-1, 1)
• (0, -2)
• (2, 0)

Write the system of equations

Solve by elimination:

7x + y = -9

-3x - y = 5

• No solution

• (1,8)

• (-1,-3)

• (-1,-2)

• x 

• y 

• either one, they are the same

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.

• 4

• 2

• 1

• -2

• You dont multiply to eliminate variables

• You will multiply one equation

• You will multiply both equations

• No need to multiply

If a system of linear equations has one solution, what does this mean about the two lines? 

• Parallel lines
• the same line 
• Intersecting lines