Determinants Matrices Question 69
Question: If $ x\ne 0 $ , $ y\ne 0 $ , $ z\ne 0 $ and , then $ {x^{-1}}+{y^{-1}}+{z^{-1}} $ is equal to
Options:
A) $ -1 $
B) $ -2 $
C) $ -3 $
D) none of these
Show Answer
Answer:
Correct Answer: C
Solution:
- [c] $ =2xyz( 3+\frac{1}{x}+\frac{1}{y}+\frac{1}{z} ) $ Hence, the given equation gives $ {x^{-1}}+{y^{-1}}+{z^{-1}}=-3. $
BETA
