## anonymous one year ago 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 ....

1. anonymous

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

2. anonymous

Yes

3. anonymous

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?

4. anonymous

So far so good

5. anonymous

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.