HELP ME ON THIS YOU GET 15 POINTS AND BRANLIEST IF YOU GET RIGHT!!

Create and solve a linear equation that represents the model, where squares and triangles are shown evenly balanced on a balance beam. assume the weight of a square is 1 unit and the weight of a triangle is unknown.

Which elements in the set below are integers? 12, –3⁄4,√ 25 , –7, √ 5 , 14⁄7, 9 a. 12, √ 25 , –7, 9 b. 12, √ 25 , –7, 14⁄7, 9 c. –3⁄4, 25 , √ 5 ,14⁄7 d. 12, –7, 9

What is the missing step in this proof ?