Consider the line y=-5/4x+9
what is the slope of a line parallel to this line?
what is the slope of a line perpendicular to this line?

Evaluate the expression for the given value of the variable. ∣-4b-8∣+∣-1-b^2 ∣+2b^3 ; b=-2

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.