*Only three of the four will be used and they must be in the correct order* Arrange the systems of equations that have a single solution in increasing order of the x-values in their solutions. Worth ten points!

Simplify 15(x - 4)(x -1)-3(x + 4)(x - 1) with steps

I'm confused on this could anyone me and show me what i need to do to solve it.

Adecorative window is made up of a rectangle with semicircles at either end. the ratio of ad to ab is 3: 2 and ab is 30 inches. what is the ratio of the area of the rectangle to the combined area of the semicircles? possible answers: a. 2: 3 b. 3: 2 c. 6: π d. 9: π e. 30: π