Answer
$n\sqrt {6m}$
Work Step by Step
To add or subtract radicals, we first need to make sure that the indices and radicands are the same.
We need to rewrite radicands as the product of factors of which we can take the square roots:
$5n\sqrt {6m} - 2\sqrt {4 • 6 • m • n^2}$
Take the square roots:
$5n\sqrt {6m} - 2 • 2 • n\sqrt {6m}$
Multiply coefficients:
$5n\sqrt {6m} - 4n\sqrt {6m}$
Now that we have the same indices and radicands, we can perform the operation:
$n\sqrt {6m}$
