(-x3 - x) + (6x2 + 6x - 7) expanded form

Interpret the following expression (5y^2-7)^3/(2y)^2

Plzz ! if you were constructing a triangular frame, and you had wood in the length of 4 inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood? yes or no? = explain your mathematical thinking/show your work:

Pr and pt a) pr = ps + pt b)pr = ps · pt c)(pr)2 = ps · pt