Question 706331
let speed of 1 car be x
other's speed will be x+18

They are travelling yowrads each other.

effective speed will be x+x+18

=2x+18

Distance = 510 km
speed = 2x+18
time = 3 hours

speed = distance / time

2x+18 = 510/3

2x+18= 170

2x= 170-18
2x= 152

x= 152 /2
x= 76 km/h 

add 18 to x to  find the speed of the other car