Approximately how many african-americans moved into harlem in the early twentieth century? 80,000 100,000 200,000 500,000

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.

What is x3+3x2−16x−48 divided by x−1?

Find the condition that the zeros of the polynomial f(x) = x^3+3px^2+3px+r may be in a.p.