Ill give you $10 if you answer

You paid $7.70 to the mail package that weighed 5.5 lb. right and solve any quetion to find the cost per pound ? ?

Find the roots of the polynomial function f(x) = x^3 + 2x^2 + x

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).