If r + 14 = -9, what justifies r = -23

Can someone pls ! pls answer all. no explanation needed..

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.

28 x 12 + 34 = ? it's for a test that if i fail on i will not proceed into the honor roll society i always dreamed of!me! worth 50 !