Y= 12
2x -y = 4

what is the solution of the system?

Arectangle has a width of 5 cm and a length of 10 cm. if the width is increased by 3, how does the perimeter change?

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.

Factor the polynomial by its greatest common monomial factor.