Write three expressions that are equivalent to the given expression.
7a+21

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

Find the missing variable for a parallelogram: a = latex: 32in^2 32 i n 2 h = b = 6.3 in (1in=2.54cm)

Asquare and an equilateral triangle have the same perimeter. each side the triangle is 4 inches longer than each side of the square. what is the perimeter of the square