Multiply.
-$( \sqrt { 6 } - 5 ) ( \sqrt { 5 } + 6 )$
A) $\sqrt { 30 } + 1 \sqrt { 5 } - 30$
B) $\sqrt { 30 } + 6 \sqrt { 6 } - 5 \sqrt { 5 } - 30$
C) $2 \sqrt { 30 } - 30$
D) $\sqrt { 30 } - 30$

Question

Quizplus · Accepted Answer

Use FOIL (First, Outer, Inner, Last) method to get:
\begin{align*}
(\sqrt{6}-5)(\sqrt{5}+6) &= \sqrt{6} \cdot \sqrt{5} + 6\sqrt{6} - 5\sqrt{5} - 30 \
&= \sqrt{30} + 6\sqrt{6} - 5\sqrt{5} -30
\end{align*}
Therefore, the best choice is $\boxed{	ext{(B)}}$.

Multiply - (6−5)(5+6)( \sqrt { 6 } - 5 ) ( \sqrt { 5 } + 6 )(6​−5)(5​+6)

Multiply
- $( \sqrt { 6 } - 5 ) ( \sqrt { 5 } + 6 )$