RRB NTPC Mains or Stage 2 Model Paper 10 with solutions

© examsiri.com

Question : 23 of 120

Marks: +1, -0

If

\frac{x^{2}}{b y + c z} = \frac{y^{2}}{c z + a x} = \frac{z^{2}}{a x + b y} = 1,

then the value of

a/{a+x }+b /{b+y}+c / {c +z}

is

– 1
2
1
– 2

Solution:

(c)

{x^2 }/{by+ cz}=1

⇒ x^2 = by + cz

Adding term ax on both sides

⇒ x^2 + ax = ax + by + cz

⇒ x(x + a) = ax + by + cz

⇒1/ {x+a}=x /{ax+ by+ cz}

⇒a/ {x+a}={ax} /{ ax+ by+ cz}

Similarly,

b/ {b+y}={b y }/{ax+ by+ cz}

c/ {c+z}={c z }/{ax+ by +cz}

∴

a /{x+a}+b/{y+b} +c/{z +c}

= \frac{a x}{a x + b y + c z} + \frac{b y}{a x + b y + c z} + \frac{c z}{a x + b y + c z}

= \frac{a x + b y + c z}{a x + b y + c z} = 1

© examsiri.com

Go to Question:

Prev Question

Next Question