Isolate y for substitution, and we have y=43-9x.
Substitute y in the next equation, and we have
4x+2(43-9x)=16, which leads to
4x+86-18x=16,
-14x=-70
x=5
Plug x into an equation, now that we have found the value.
9(5)+y=43
45+y=43
y=-2
Now double check our answer:
9(5)+(-2)=?
45+(-2)=43
4(5)+2(-2)=?
20+(-4)=16
So, x=5 and y=-2.
