Can someone me solving these maths problems not sure if i did it right.

Mary beth used the mapping rule to find the coordinates of a point that had been rotated 90° counterclockwise around the origin. examine the steps to determine whether she made an error. m (3, –6) is rotated 90° counterclockwise. (x, y) → (–y, x) 1. switch the x- and y-coordinates: (6, –3) 2. multiply the new x-coordinate by –1: (6(–1), –3) 3. simplify: (–6, –3) .

Simplify the algebraic expression 8y-2(y+4)

Given: prst square pmkd is a square pr = a, pd = a find the area of pmct.