Question

y-2x=8, 2y+x=1

Answer 1

This is the substitution method

y-2x=8 (1)
2y+x=1 (2)

From equation (1) y-2x=8 would now be y=8+2x you can call this equation (3)

so now, we substitute equation (3) in equation (2)

2(8+2x)+x=1
16+4x+x=1
16+5x=1
5x=1-16
5x=-15
x=-15/5
x=-3

for x=-3, substitute it in equation (3)

y=8+2(-3)
y=8-6
y=2

x=-3,y=2