Q If x^2 +5y^2 +z^2=2y(2x+z) then which of the following must be true.
a)x=2y b)x=2z c)2x=z
a)only a b)only b c) a and b both d)none
a)x=2y b)x=2z c)2x=z
a)only a b)only b c) a and b both d)none
x² + 5y² + z² = 2y(2x + z)quantskillsgmat wrote:Q If x^2 +5y^2 +z^2=2y(2x+z) then which of the following must be true.
a)x=2y b)x=2z c)2x=z
a)only a b)only b c) a and b both d)none
x² + 5y² + z² - 4xy - 2yz = 0
(x² - 4xy + 4y²) + (z² - 2yz + y²) = 0
(x - 2y)² + (z - y)² = 0
x = 2y and z = y or z = x/2 implies x = 2z
So, (a) and (b) both hold true.
The correct answer is C.
