Is this a function or no ?

Translate the word phrase into a math expression. 15 fewer than the product of 4 and a number. (pls immediately)

Which of the following points is collinear with (-2,1) and (0,3)

Angle xyz is formed by segments xy and yz on the coordinate grid below: a coordinate plane is shown. angle xyz has endpoints at 3 comma negative 1 and 6 negative 2 and 3 comma negative 3 and measures 36.87 degrees. angle xyz is rotated 270 degrees counterclockwise about the origin to form angle x′y′z′. which statement shows the measure of angle x′y′z′?