What is a many to one function ?

Agiven line has the equation 2x + 12y = −1. what is the equation, in slope-intercept form, of the line that is perpendicular to the given line and passes through the point (0, 9)? y = ( )x + 9

Segment xz is bisected by point y. if xy = 12x, and the measure of xz = 18x – 6, solve for x

The hawaiian alphabet has 12 letters. how many permutations are posible for each number of letters?