Dose anyone have an answer key to plato? for geometry at least

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.

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)

Is the underlined participial phrase correctly placed or misplaced? i smelled each and every flower strolling through the garden. a. correctly placed participial phrase b. misplaced participial phrase