Answer
$-6x+9$
Work Step by Step
We are given the expression $-9+4x+18-10x$. We can group like terms and combine them in order to simplify the expression.
$(4x-10x)+(-9+18)=(4x+(-10x))+(18-9)=(-6x)+(9)$
Finally, we can recombine the like terms into one expression without parentheses.
$-6x+9$
