7out of 11 people are at the beach with their umbrellas their are 99 people how many do not have an umbrella?

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

How many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

Find the measure of the interior angles of the following regular polygons: a triangle, a quadrilateral, a pentagon, an octagon, a decagon, a 30-gon, a 50-gon, and a 100-gon.