Call the distance between the edge of the frame and the edge of the picture 'x'. The picture's length is now 12-2x and the width 10-2x. Therefore the product of these two are 80.
Solve for x.
"A picture frame is 12 inches by 10 inches. If the picture that is showing in the frame is 80 square inches, and the frame is the same width on all sides, what are the dimensions of the picture?"
Ahh where do I even start here? So far I got this:
F(frame) = 120 in
P(picture) = 80 in
What do I even do here? I'm not sure!
Divide through by 4 first to make things easier!
Now what you want to do is arrange in standard quadratic form:
Now factor...can you think of two factors of 10 whose sum is -11?
You will get two roots, but only 1 will make sense in the context of the problem.