You are solving for the height. Use the formula:
c² - b² = a² in which c = hypotenuse
(13)² - (5)² = a²
Simplify
169 - 25 = a²
144 = a²
Isolate the a. Root both sides
√144 = √a²
a = √144
a = √(12 x 12)
a = 12
C) 12 feet is your answer
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This can be factored into (x+9)(x+5)/(x+9)(x+1)
once simplified, it's (x+5)/(x+1)
The denominator cannot be negative, so x≠-1
Therefore, the answer is C.
I got 65/153 since you actually multiply by the reciprocal of the second fraction.