Question

If $|x^2+3x-4|=|x+4|$, then $x=$

• A. $-4$
• B. $2$
• C. $-2$
• D. $0$

Answer 1

Answer: (A), (B), (D)

The correct options are
A $-4$
B $2$
D $0$

$|x^2+3x-4|=|x+4|\Rightarrow (|x+4|)(|x-1|)=|x+4|\Rightarrow (|x+4|)(|x-1|-1)=0\Rightarrow |x-1|=1\text{or}|x+4|=0\Rightarrow x-1=\pm 1\text{or}x+4=0\Rightarrow x=2,0,-4$