I need some help please What's |5| + |–7|?

Find the sum of the first 8 terms of the following sequence. round to the nearest hundredth if necessary.

The diameter of a ball is 8 in. what is the volume of the ball? use 3.14 for pi. enter your answer as a decimal in the box. round only your final answer to the nearest hundredth.

Which expression is equivalent to7_/x^2 ÷ 5_/y^3? assume y# 0