Question

Please help me. I need how to do the problem too

Answer 1

Answer: Choice A.  (8, 4)

==========================================================

Explanation:

Because x = 2y, we can replace every copy of x with 2y

Let's do so in the second equation

3x - 4y = 8

3(x) - 4y = 8

3(2y) - 4y = 8 .... x replaced with 2y; now let's isolate y

6y - 4y = 8

2y = 8

y = 8/2 ..... divide both sides by 2

y = 4

Use this y value to find x

x = 2y

x = 2*4

x = 8

So we have x = 8 and y = 4 pair together to get the answer (x,y) = (8, 4) which is choice A.