Solve for a 0.25e - 0.5 = 4.5

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?

Evaluate cos2θ for cosθ = square root of 3/2

Ineed to know the answer to this algebra question.