-7/8+(-3/4)

how do i evaluate that question?

Find the length of the diagonal of the rectangle. round your answer to the nearest tenth. || | | 8 m | | | | 11 m

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)

If you were constructing a triangular frame, and you had wood in the length of 4inches, 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