Question

x + 5y = -2
2x + y = 5

The point of intersection of the lines has a y-coordinate of _____.

-1
1
3

Answer 1

Choose your method: elimination by addition/subtraction, substitution, graphing.

Answer 2

I think it is 3 because if you add the two equations using the Addition method.
x + 5y = -2
2x + y = 5
----------
3x + 6y = 3

IS this correct?

Answer 3

Your goal is to eliminate one of the variables. Unfortunately, what you have done has not eliminated either x or y. Think this through.

Answer 4

Okay, So then

x + 5y = -2
2x + y = 5
----------
-1x + 4y = -7

Would this be correct?

Answer 5

Have you eliminated either x or y?

Answer 6

Hint: Multiply every term of the first equation by -2. Results?

Answer 7

-2(x + 5y = -2) = ?

Answer 8

From what I know, the equation in the Parentheses is solved with the solution being -2, Though the variables have not yet been solved for it. Based on what I know, would the equation be simplified to -2 x -2?

Answer 9

still need help?

Answer 10

Rather than respond to y our comment, I ask you again to multiply the first equation by -2 and to ask you to think about why this may be a good approach.

x + 5y = -2
2x + y = 5

-2(x+5y=-2) = ?

Add your result to the second equation and see what happens to the variable x.