Find the arc length of the semicircle. 11

Find the solution of this system of equation -7x+y=-20 9x-3y=36

Lena reflected this figure across the x-axis. she writes the vertices of the image as a'(−2, 8), b'(−5, 6), c'(−8, 8), d'(−4, 2).

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1