ANSWER
Length (x) = 25 feet
Step-by-step explanation
Given:
Desired Outcome:
Length (x) of the ladder
Solve for Length (x) using Pythagoras Theorem
when x = 13
x - 1 = 13 - 1 = 12
x - 18 = 13 - 18 = -5 (length cannot be negative)
when x = 25
x - 1 = 25 - 1 = 24
x - 18 = 25 - 18 = 7
Hence, the length of the ladder is 25 feet.