1 140 = 5(x+0.9x)= 5x 1.9x = 9.5x
The solution is x =120km/h.
5)A completed every hour1/3/4 =112.
B per hour 1/4/5= 1/20.
AB cooperates to complete every hour112+1/20 = 2/15.
It takes (2/3) ÷ (2/15) = 5 hours to complete 2/3.
The famous saying of "Mathematics 10" is: Mathematics is an evolutionary culture, mathematics is all kinds of proof skills, and mathematics is the highest form of k