Question

4+x+=2x-2y
x-y+19=2x+2y

Answer 1

4+x=2x-2y
x-y+19=2x+2y

x-2x=-2y-4
-x=-2y-4
x=2y+4

2y+4-y+19=2*(2y+4)+2y
y+4+19=4y+8+2y
-5y=-23+8
-5y=-15
y=3 podstawiamy pod równanie x=2y+4
x=2*3+4
x=6+4
x=10