Help me - I’m stuck on this problem

Question

A triangle has a perimetwe of 31 inches . The longest side is 1 inch less than twice the shortest , and the third side is 4 inches longer than the shortest side find the length of the sides 

Answer 1

s + 2s - 1 + s + 4 = 31

 

4s + 3 = 31

4s + 3 - 3 = 31 - 3

4s = 28

4s/4 = 28/4

s = 7

 

2(7) - 1 = 14 - 1 = 13

 

7 + 4 = 11

Answer 2

Let L, M, and S be the sides (longest, middle, and shortest). Then set up a system of equations and solve them. For example, since the perimeter is 31 inches, one of the equations would be L + M + S = 31.