Question 336961
y=130-2x
y=10+4x
..
multiply first equation by 2 and add both equations
2y=260-4x
y=10+4x
add
3y=270
divide by 3
3y/3 =270/3
y=90
..
90=10+4x
add -10
90-10= 10-10 +4x
80 =4x
divide by 4
80/4 = 4x/4
x=20