Bunuel wrote:
brandon7 wrote:
Bunuel wrote:
Is\(|x|=y-z\) ?
Note that\(y-z\) must be\(\geq{0}\) , because absolute value (in our case\(|x|\) ) can not be negative.
Generally question asks whether\(y-z\geq{0}\) and whether the difference between them equals to\(|x|\) .
(1)\(-x=y-z\)
if\(x>0\) -->\(y-z\) is negative --> no good for us;
if\(x\leq{0}\) -->\(y-z\) is positive --> good.
Two possible answers not sufficient;
(2)\(x<0\)
Not sufficient (we need to know value of y-z is equal or not to |x|)
(1)+(2) Sufficient.
Answer: C.
Note that\(y-z\) must be\(\geq{0}\) , because absolute value (in our case\(|x|\) ) can not be negative.
Generally question asks whether\(y-z\geq{0}\) and whether the difference between them equals to\(|x|\) .
(1)\(-x=y-z\)
if\(x>0\) -->\(y-z\) is negative --> no good for us;
if\(x\leq{0}\) -->\(y-z\) is positive --> good.
Two possible answers not sufficient;
(2)\(x<0\)
Not sufficient (we need to know value of y-z is equal or not to |x|)
(1)+(2) Sufficient.
Answer: C.
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