Subtract the radical expressions. Assume that all variables represent positive real numbers. $3 \sqrt { 72 y ^ { 3 } } - \sqrt { 2 y }$
A) $17 \sqrt { 2 y ^ { 3 } - 2 y }$
B) $3 \sqrt { 72 y ^ { 3 } - 2 y }$
C) $( 18 y - 1 ) \sqrt { 2 y }$
D) Cannot be simplified further

Question

Quizplus · Accepted Answer

First, simplify $3 \sqrt { 72 y ^ { 3 } }$ by factoring inside the radical to get $3 \sqrt { 36 \cdot 2 y^3 }$, which simplifies to $3 \cdot 6y \sqrt { 2 y }$ or $18y \sqrt { 2 y }$. Then, subtract $\sqrt { 2 y }$ from it to get $(18y - 1) \sqrt { 2 y }$.

Subtract the Radical Expressions 372y3−2y3 \sqrt { 72 y ^ { 3 } } - \sqrt { 2 y }372y3​−2y​

Subtract the Radical Expressions $3 \sqrt { 72 y ^ { 3 } } - \sqrt { 2 y }$