Is -13.1 + (-19) rational or irrational

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

Due to bad planning, two of the local schools have their annual plays on the same weekend. while 457 people attend one, and 372 attend the other, only 104 people were able to attend both. how many people went to at least one play?

Four quarts of a latex enamel paint will cover about 200 square feet of wall surface. how many quarts are needed to cover 98 square feet of kitchen wall and 52 square feet of bathroom wall