There are 39 pens in 3 boxes. how many pens are in 12 boxes?

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 h(x) = f[tex]h(x) = f[/tex] ° [tex]g) (x)[/tex] and [tex]h(x) = \sqrt[3]{x+3}[/tex], find [tex]g(x)[/tex] if [tex]f(x) = \sqrt[3]{x +2}[/tex] ·

]supplementary angles are two angles that add up to . • complementary angles are two angles that add up to degrees. • adjacent angles share a and a • congruent angles have the measure. • an triangle has one angle that is greater than 90 degrees. • a triangle with angles 45°, 45°, and 90° would be a triangle