Carcass wrote:
If |x + 3| = 12 and x is a multiple of 5, what is the value of x ?
There are 3 steps to solving equations involving ABSOLUTE VALUE:
1. Apply the rule that says:
If |x| = k, then x = k and/or x = -k2. Solve the resulting equations
3. Plug solutions into original equation to check for extraneous roots
So, if |x + 3| = 12, then EITHER x + 3 = 12 OR x + 3 = -12
If x + 3 = 12, then
x = 9If x + 3 = -12, then
x = -15So,
x = 9 or
x = -15Since we're told x is a
multiple of 5, we can conclude that x = -15
A quick check will verify that this solution is correct.
Answer:
Cheers,
Brent
_________________
Brent Hanneson - founder of Greenlight Test Prep
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