If $\sqrt{5+11-7}=\sqrt{5+11}-\sqrt{x}$, then the value of $x$ is
(A) 1
(B) 7
(C) -7
(D) 49
(E) 4
If $\sqrt{5+11-7}=\sqrt{5+11}-\sqrt{x}$, then the value of $x$ is
(A) 1
(B) 7
(C) -7
(D) 49
(E) 4

## Solution

$$
\begin{aligned}
\sqrt{5+11-7} & =\sqrt{5+11}-\sqrt{x} \\
\sqrt{9} & =\sqrt{16}-\sqrt{x} \\
3 & =4-\sqrt{x} \\
\sqrt{x} & =1 \\
x & =1
\end{aligned}
$$

ANSWER: (A)