Add or subtract by first simplifying each radical and then combining any like radicals. Assume that all variables represent positive numbers.
-$6 \sqrt { 5 }$+$2 \sqrt { 20 }$
A)-$2\sqrt { 5 }$
B)$10 \sqrt { 5 }$
C)-$10 \sqrt { 5 }$
D)$8\sqrt { 5 }$

Question

Quizplus · Accepted Answer

The expression $2 \sqrt { 20 }$ simplifies to $2 \cdot 2\sqrt { 5 } = 4\sqrt { 5 }$ because $20 = 4 \cdot 5$ and $\sqrt { 4 } = 2$. Adding this to $6 \sqrt { 5 }$ gives $6\sqrt { 5 } + 4\sqrt { 5 } = 10\sqrt { 5 }$.

Add or Subtract by First Simplifying Each Radical and Then 656 \sqrt { 5 }65​

Add or Subtract by First Simplifying Each Radical and Then $6 \sqrt { 5 }$