Question

Combine these radicals. 3 square root of 2 -5 square root of 2

Answer 1

You can see that both terms involve the square root of two. Think of it as a variable, say x. Your expression becomes

$3\sqrt{2}-5\sqrt{2} \to 3x-5x = x(3-5) = x(-2) = -2x \to -2\sqrt{2}$