Use substitution method to solve for
y=3/2x-1
y=4x+4
The correct answer is (-2,-4) but I ended up with 8/3x=-5 ....

Question

anonymous · Answer

Is the second equation supposed to say $y=4x+4$?

anonymous · Answer

Yes

anonymous · Answer

Okay. It doesn't matter which equation you substitute into which, so I'll just take the first one.
$$y=\frac{3}{2}x-1$$
You can solve for $x$, or leave it alone. I'll leave it alone. Plug it into the second equation:
$$y=4x+4~~\implies~~\frac{3}{2}x-1=4x+4$$
Good so far?

anonymous · Answer

So far so good

anonymous · Answer

Okay, now you solve for $x$:
$$\begin{align*}
\frac{3}{2}x-1&=4x+4\
\frac{3}{2}x-4x&=4+1\
\left(\frac{3}{2}-4\right)x&=5\
\left(\frac{3}{2}-\frac{8}{2}\right)x&=5\
-\frac{5}{2}x&=5\
x&=-\frac{2}{5}\times5\
x&=-2
\end{align*}$$
You can easily find $y$ now.