Question 665715
y-2x=9
y-7x=8
y=7x+8

substitute y in first equation

7x+8-2x=9
5x+8=9
5x+8-8=9-8
5x=1
x=1/5

plug x in any equation

y=7x+8
y=7*(1/5)+8
y=(7/5)+8
y=47/5