The product of the -72 could be set up at -72=-9(x).
Divide -9 from both sides and you get the unknown value (x) to be 8
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.
If the pattern continues, it could be 2.75 * 63.63 repeating to get to the end of the card. The second answer is 63. When she started the card, she had $175. Divide 175 by 2.75 and you get 63 repeating.