Atriangle has one side that measures x, another side that measures 2x, and a third side that measures 5 less than x. the perimeter is 31 inches. which equation would you use to find the value of x? explain your answer a. x + 2x + x - 5 = 31 b. x + 2x + x + 5 = 31 c. x + 2x - x - 5 = 31 d. x + 2x - x + 5 = 31