E=mc2 solve for c can someone me solve for c?

For one history test, keith had to answer 40 questions. of these 40 questions, keith answered 28 of them correctly. what percent did keith get on his history test? round your answer to the nearest tenth if necessary

Gail is making costumes for a school play. each rabbit costume needs one and one half yards of white fur fabric, a yard of blue striped fabric, and a quarter of a yard of pink felt for the ears. g? ail needs to make eight rabbit man yards will she need, for the white fur fabric, blue striped fabric, and pink felt?

What is the value of x in the following equation. -x ^3/2 = -27