Translate to an algebraic expression. 45 less than b

This is different from the first one can someone me

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

Solve each quadratic equation by factoring and using the zero product property. x^2 - 8x + 30 = 3x