Question
Quantitative Aptitude Question on Number Systems
If u2+(u-2v-1)2 = -4v(u+v),then what is the value of u+3v?
A
1/4
B
0
C
1/2
D
-1/4
Answer
-1/4
Explanation
Solution
The correct answer is (D):
u2+(u-2v-1)2=-4v(u+v)
⇒ u2+u2+4v2+1-4uv+4v-2u+4vu+4v2 = 0
⇒ 2u2-2u+8v2+4v+1 = 0
⇒ 2(u2-u+1/4)+2(4v2+2v+1/4) = 0
⇒ 2(u-1/2)2+2(2v+1/2)2 = 0
⇒ u-1/2 = 0;2v+1/2 = 0
u = 1/2 and v = -1/4
u+3v = 1/2 - 3/4 = -1/4