Question 345414
let east bound car travel x
north bound car travels x+70 in the same time.
the distance between cars = 170 miles 
....
x^2+(x+70)^2= 170^2
x^2+140x+4900 = 28900
x^2+140x+4900-28900 =0
x^2+140x-24000 = 0
x^2+240x-100x-24000=0
x(x+240)-100(x+240)=0
(x+240)(x-100)=0
x=100 OR x = -240. Ignore negative value.
east bound car has traveled 100 miles
north bound has traveled x+70 = 100+70 170 miles.