Question

I'm confused about graphing or solving the linear equations for slope/intercept.

Here is what I solved:
3x+2y=-6 X-4y=-16

2y= -3x-6 -4y=1x-16

Y=-3/2+3 Y=+1/4+4
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My answer for graphing the systems for the lines to intersect...well, they didn't intersect. But the answer is (4,-1)

Can someone explain my problem? And help explain how to solve it?

Answer 1

try playing around here, where I have plotted the first pair...

http://www.wolframalpha.com/input/?i=plot+3x%2B2y%3D-6,+x-4y%3D-16

since your lines have different slopes, the have to intersect. You must have plotted them wrong.

3x+2y = -6
x-4y = -16

2y = -3x-6
-4y = -x-16

You went wrong here. Why did you just drop the x stuff?
Y= -3/2 x - 3
y = 1/4 x + 4

Now equate the two expressions for y:

-3/2 x - 3 = 1/4 x + 4
-7/4 x = 7
x = -4
so, y=3

If the answer is (4,-1) you have some typos in the original equations.