Answer
The subtraction sign changes the sign of each term; $7r+2$
Work Step by Step
The distributive property states that $a(b+c)=ab+bc$ (where $a$, $b$, and $c$ are real numbers). Therefore, $-(-4r+6)=(-1\times-4r)+(-1\times6)=(4r)+(-6)=4r-6$.
In other words, the -1 is distributed to both terms in parentheses, which changes the sign of each term.
$(3r+8)+4r-6=(3+4)r+(8-6)=(7)r+(2)=7r+2$
