Carcass wrote:
\(|4x+24|= 96\)
\(|4x|=120\)
Quantity A |
Quantity B |
x |
18 |
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
GIVEN: |4x+24|= 96
So, EITHER 4x + 24 = 96 OR 4x + 24 = -96
If 4x + 24 = 96, then x = 18
If 4x + 24 = -96, then x = -30
Both x-values work upon testing
GIVEN: |4x|= 120
So, EITHER 4x = 120 OR 4x = -120
If 4x = 120, then x = 30
If 4x = -120, then x = -30
Both x-values work upon testing
IMPORTANT: Only ONE value (x = -30) satisfies BOTH equations, so x MUST equal -30
We get:
QUANTITY A: -30
QUANTITY B: 18
Answer: B
Cheers,
Brent
_________________
Brent Hanneson - founder of Greenlight Test Prep