Can someone like solve this?
help pls
(dont guess pls)

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.

Maurice has 54 fewer comic books than rebecca. they have 130 comic books together .how many comic books are in maurices collection ? how many comic books are in rebeccas collection

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?