use substitution to solve system

Question

-2x+y= -9
=5x+4y= -30

Answer 1

hmmm. you must really be confused; not only at a loss, but at a lost!

we see that
-2x+y = -9, so
y = 2x-9

now substitute that into the other equation:

5x+4(2x-9) = -30
13x = 6
x = 6/13
so, y=2x-9 = -105/13

The =5x+4y confuses me. If that was supposed to be -5x, then

-5x+4(2x-9) = -30
3x = 6
x=2

which seems like a better answer.