Can someone tell me a pair of opposite rays on this?

In trapezoid efgh, m∠hef=(4x2+16)∘ and m∠gfe=(5x2+12)∘. find the value of x so that efgh is isosceles. i'm desperate.

If a company produces x units of an item at a cost of $35 apiece the function c=35x is a of the total production costs

Mr. rose asked his students to draw a quadrilateral with 4 unequal sides. draw an example of this kind of quadrilateral.