Question

2x + y = 7
5x + y = 9
Solve the system of equations.

(-2/3, 25/3)

(2/3, 17/3)

(2/3, 25/3)

Answer 1

Try multiplying the first equation by -1... then adding the result to the second equation.

Answer 2

What?

Answer 3

You have a system of equations. One of the methods to solve them is by manipulation.

So, multiply eq 1 by -1.. like this:

-1(2x+y) = -1(7)
-2x - y = -1

Now add that to the second equation
-2x - y = -1
5x + y = 9
3x = 8
x = 8/3

Now substitute the x value into either equation to get y.

Answer 4

8/3 isn't one of the answer choices.

Answer 5

Sorry, I typed too quick..

-1(2x + y) = -1(7)
-2x - y = -7

Adding
-2x - y = -7
5x + y = 9

results in:
3x = 2
x = 2/3

Then substitute. Very sorry!!!

Answer 6

No worries:)