Question

How do I work this out

Answer 1

P = a + b + c where a < b < c

P = 42 in
b = 18 in
a = x
c = 4x - 1

The equation:

x + 18 + 4x - 1 = 42    |combine items

5x + 17 = 42      |subtract 17 from both sides

5x = 25    |divide both sides by 5

x = 5 (in)

c = 4 · 5 - 1 = 20 - 1 = 19 (in)

Answer: The length of the longest side is 19 in.