Answer:
1. 5
2. 5
3. -3
4.y= -1
5. 5
Explanation:
1.)x- 2y= -25 ; y=3x
x-2(3x)=(-25)
x-6x=(-25) ; -5x=(-25) ; x=5
2.) 5x+3y =40; x=y
8y=40; y=5
3.) 4x-3y= -27; x=3y
4(3y)-3y= -27; 12y-3y=-27; 9y=-27; y=-3
4.)x-y=9; x=-8y; -8y-y=9; -9y=9; y=-1
5.) 2x+2y=30; y=2x ; 2x+2(2x)=30; 6x=30; x=5