# How do you simplify -3sqrt17-4sqrt17?

$- 3 \sqrt{17} - 4 \sqrt{17} = - 7 \sqrt{17}$
We simply could have written $- 3 x - 4 x = - 7 x$.
And if $x = - \sqrt{17}$ (or any value of $x$), then $- 7 x = - 7 \sqrt{17}$.