Answer:
−7r^(2)+12r+10x−18
Step-by-step explanation:
Grab the original equation: 10x+7r−r^(2)−6r^(2)−18+5r
For subtraction bits, treat them as negatives: 10x+7r+−r^(2)+−6r^(2)+−18+5r
Combine like terms: (−r^2+−6r^2)+(7r+5r)+(10x)+(−18)
Simplify that, and you get your final answer: −7r^(2)+12r+10x+−18
