1) Write the algebraic expressions for: a) Subtract the product of 2 and x from 7
b) 6 more than the product of 3 and y
c) Difference of a and b added to 6
d) 7 times m added to 5 times n​

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.

Can anyone explain to me how to do this? anything will .

What number gives you a irrational number when added to 2/5