Yoko has scored 81 , 84 , 84 , 69 , and 76 on her previous five tests. what score does she need on her next test so that her average (mean) is 81 ?

Prove that 3: 8 is equivalent to 12: 32.a. use diagrams to support your answer.

The volume of a box varies directly with its length if a box in the group has a length of 30inches and k=24 what is its volume

Parabolas y=−2x^2 and y=2x^2+k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.