Question

If x=y=z , then $\frac{(x+y+z)^2}{x^2+y^2+z^2}$ is:

• A. 2
• B. 3
• C. 1
• D. 4

Answer 1

Answer:

B. 3

Solution:

Given $x=y=z$

Let $x=y=z=k$

To find: $\frac{(x+y+z)^2}{x^2+y^2+z^2}$

$=\frac{(k+k+k)^2}{k^2+k^2+k^2}$

$=\frac{(3k)^2}{3k^2}$

$=\frac{9k^2}{3k^2}$

$=3$

Hence option(B) is the correct answer.