Perform the indicated operations.
-$- 3 \sqrt { 180 } - 7 \sqrt { 45 }$
A) $3 \sqrt { 5 }$
B) $39 \sqrt { 5 }$
C) $- 39 \sqrt { 5 }$
D) $- 3 \sqrt { 5 }$

Question

Quizplus · Accepted Answer

First, simplify the square roots: $\sqrt{180} = \sqrt{36 \times 5} = 6\sqrt{5}$ and $\sqrt{45} = \sqrt{9 \times 5} = 3\sqrt{5}$. Then, substitute these into the original expression to get $-3(6\sqrt{5}) - 7(3\sqrt{5}) = -18\sqrt{5} - 21\sqrt{5} = -39\sqrt{5}$.

Perform the Indicated Operations −3180−745- 3 \sqrt { 180 } - 7 \sqrt { 45 }−3180​−745​

Perform the Indicated Operations $- 3 \sqrt { 180 } - 7 \sqrt { 45 }$