1. ## System of equations....

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

2. Originally Posted by topaz192
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:
$x - 9 = 3x + 7$

$2x = -16$

$x = -8$.

Now use x = -8 in either one of the original equations:
$y = 3(-8) + 7 = -24 + 7 = -17$

So the solution is (x, y) = (-8, -17).

-Dan