Question

Please help, I really don't get this​

Answer 1

9514 1404 393

Answer:

  (-8, -8)

Step-by-step explanation:

We notice that the coefficients of y are +4 and -4, so have a sum of zero. This means we can add the two equations to eliminate the y-terms.

  (-7x +4y) +(4x -4y) = (24) +(0)

  -3x = 24 . . . . . . . . . simplify

  x = -8 . . . . . . . . . . . divide both sides by -3

Now, we can find y using either equation.

  4(-8) -4y = 0

  -8 -y = 0 . . . . . . . . divide both sides by 4

  -8 = y . . . . . . . . . . add y to both sides

The solution to the system of equations is ...

  (x, y) = (-8, -8)

Answer 2

Answer:

-8, -8

Step-by-step explanation:

If you add the equations, you get -7x + 4x + 4y - 4y = 24. Canceling out the 4y and the -4y, and adding 4x to -7x, you get -3x = 24. Divide both sides by -3 and you get x = -8. Next, pick an equation and substitute x for -8. I am going to use the first equation. (-7)-8 + 4y = 24 is equal to 56 + 4y = 24. Subtract 56 from both sides to get 4y is equal to -32, and if you divide both sides by 4, you get y = -8.