Write an algebraic expression that represents the perimeter of the figure shown: (simplify your answer. Type an expression using \"b\" as the variable.) 4b Equilateral triangle Equilateral triangle square Use an algebraic equation to find the measure of each angle that is represented in terms of x. 120 X+10 X+10 x x 140 Which is more economical: purchasing the economy size of a detergent at 66 kilograms for $6.15 or purchasing the regular size at 780 grams for .60? How much less per gram is the correct choice. (