Acar dealership has 40 cars on the lot, 30% of which are silver. if the dealership receives a new shipment of 80 cars, 40% of which are not silver, what percent of the total number of cars are silver?

i got 10.28 but that rounds up to 10.3

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.