Please help me, i dunno what to do

The formula for the volume of a rectangular prism is v = lwh. a rectangular prism has a length of 2y 3 and width of 5y. the volume of the prism is 20y 10 + 70y 4 . what is the height of the prism? show your work.

Choose the triangle with x equal to 17.

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)