Answer:
C. x = -25 or x = 7
Explanation:
5|x + 9| = 80
Divide both sides by 5.
|x + 9| = 16
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To solve an absolute value equation of the form
|X| = k
where X is an expression in x and k is a non-negative number, solve the following compound equation
X = k or X = -k
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In our case, X = x + 9, and b = 16.
To solve our absolute value equation, we set x + 9 equal to 16 and x + 9 equal to -16.
|x + 9| = 16
x + 9 = 16 or x + 9 = -16
Subtract 9.
x = 7 or x = -25
Answer: C. x = -25 or x = 7