Question #b8d66

2 Answers
Feb 6, 2018

y=4

x=2

Explanation:

If 4x-2y=0 and 4x+y=12, then:

4x-4x+y-(-2y)=12-0

=> 0x+y+2y=12

=> 3y=12

=> y=4

Since

4x+y=12

we get that

4x+4=12

=> 4x=12-4

=> 4x=8

=> x=2

So y=4 and x=2.

Feb 6, 2018

x=2 and y=4

Explanation:

Notice that the x terms are exact;y the same in both equations.

If you subtract the equations, the x terms will be eliminated and you will be able to solve for y

" "4x +y =12" "rarr A
" "4x -2y =0" "rarr B

A-B:" " 0x+3y =12" "rarrC

color(white)(wwwwwwwwwww)y = 4

Once you know the value for y you can use it to find x

Substitute 4 " for " y " in " A

" "4x +y =12" "rarr A
" "4x +(4) =12

" "4x = 8
" "x =2

Check in B

" "4x -2y =0" "rarr B
" "4(2) -2(4) =0
" "8-8=0