If x - y + z = 0, then what is the value of (x2 + yz) ÷ (x2 + y2 + z2)?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. .
x - y + z = 0
⇒ y = x + z
(x2 + yz) ÷ (x2 + y2 + z2)
= [x2 + (x + z)z] ÷ [x2 + (x + z)2 + z2]
= [x2 + xz + z2] ÷ [2x2 + 2xz + 2z2]
= [x2 + xz + z2] ÷ [2(x2 + xz + z2)]
= 1/2