Step-by-step explanation:
a) (4×20)-90= 80-90= -10 -> 460:10= 46+ 1(they were $10 short) = 47 cars
b) (15×20)-90= 210 -> 460-210 = 250 -> 250÷10= 25
c) (21×20)-90= 330 -> 460-330= 130-> 130÷10= 13
d) (27×20)-90= 450-> 460-450= 10 -> 10÷10=1
e) (t×20)-90= 20t-90 -> 20t - 540 -> (20t-540)/10
