Question 67695

Let x= speed of first car
Then x+5=speed of other car


distance(d)=rate(r)   times   time(t) or d=rt

Distance first car travelled=78x=1.3x (expressed in hours)
Distance second car travelled =144(x+5)=2.4(x+5) (expressed in hours)



Now we are told that the faster car went twice as far as the slower car.  So our equation to solve is:

2.4(x+5)=2(1.3x)  clear parens

2.4x+12=2.6x  subtract 2.4x from both sides

0.2x=12
x=60 kmh--speed of first car

1.3x=1.3(60)=78km-------------------------distance travelled by 1st car

x+5=60+5=65 kmh  speed of other car

2.4(x+5)=2.4(65)=156 km -------------------distance travelled by other car

ck

156=2(78)
156=156


Hope this helps----ptaylor