Question 181983
{{{(-3r^2 +2r +4) - (7r^2 +4)}}} Start with the given expression.



{{{-3r^2 +2r +4-7r^2-4}}} Distribute



{{{(-3r^2-7r^2) +2r +(4-4)}}} Group like terms.



{{{-10r^2+2r}}} Combine like terms.



So {{{(-3r^2 +2r +4) - (7r^2 +4)=-10r^2+2r}}}