I think the answer is 8x. I am not 100% sure
Let s = the speed of the slower train in km/hrs+10 = the speed of the faster train in km/hrLet t = time in hrs for the slower train to go 160 kmt-5 = time in hrs for faster train to go 160 km---------------Slower train:(1)
160=s.t
Faster train:(2) 160=(s+10) .(t-.5)From (1)(1) t=160/s
use the relations given in following screenshot and then use quadratic equation.
This is the awnser too this one
Each just has different amounts of 0s
You would multiply 4 by 72 then u multiply 4 * -6 then after that you would add 15