Answer:
x = 5
Step-by-step explanation:
Remember the rule: 5, 12, 13
To prove this rule: Use the equation a² + b² = c²; where as a & b = shorter side, and c is the hypotenuse (longest).
Solve. Let a = x, b = 12, c = 13
a² + b² = c²
(x)² + (12)² = (13)²
Simplify
x² + 144 = 169
Isolate the x. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
x² + 144 (-144) = 169 (-144)
x² = 169 - 144
x² = 25
Isolate the x. Root both sides
x² = 25
√(x²) = √(25)
x = √25 = √(5 * 5) = 5
5 is your answer for x
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