Carcass wrote:
If \(x^2-4x=12\), what is the value of \(|x-2|\)?
Given: \(x^2-4x=12\)
Set the quadratic equal to zero: \(x^2-4x-12=0\)
Factor: \((x-6)(x+2)=0\)
So, EITHER \(x = 6\) OR \(x = -2 \)
Since numeric entry questions can have only one correct answer, we know that the two possible x-values will yield the same value of \(|x-2|\).
That is, if \(x = 6\), then \(|x-2|=|6-2|=|4|=4\)
Similarly if \(x = -2\), then \(|x-2|=|(-2)-2|=|-4|=4\)
Answer: 4
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Brent Hanneson - founder of Greenlight Test Prep