Step-by-step explanation:
factory A manufacturers 500 cars more than 3 times cars manufactured by factory B.
A=500+3(B)
A manufactures 3500 cars=A=350p cars
B=?
plug value of A in the above equation
3500=500+3B
minus 500 from both sides
3000=3B
divide each side by 3
1000=B
B=1000 cars
Factory B manufactures 100 cars
