#### Answer

True

#### Work Step by Step

We simplify the expression by factoring out $\sqrt 2$ as it is a part of all of the terms in the expression:
$3\sqrt 2-5\sqrt 2+\sqrt 2$
=$\sqrt 2(3-5+1)$
=$\sqrt 2(-2+1)$
=$\sqrt 2(-1)$
=$-\sqrt 2$
The expression does indeed reduce to $-\sqrt 2$.