Question 155080
3.5(x+x+10)=455
3.5(2x+10)=455
7x+35=455
7x=455-35
7x=420
x=420/7
x=60 mph for the slower car.
60+10=70 mph for the faster car.
Proof:
3.5(60+70)=455
3.5*130=455
455=455