Ok, i was just on a site for tutoring but it isn't making much sense to me!
What steps do i follow through when doing this?
y=3x+7
y=x-9
There are several ways, the one I favor most is this:
The two y values are equal, so let them be equal:
$\displaystyle x - 9 = 3x + 7$
$\displaystyle 2x = -16$
$\displaystyle x = -8$.
Now use x = -8 in either one of the original equations:
$\displaystyle y = 3(-8) + 7 = -24 + 7 = -17$
So the solution is (x, y) = (-8, -17).
-Dan