Can someone please help me with this question? Kareem took 5 h to drive 470km from Sudbury to Brantford. For part of the trip, he drove at 100 km/h. For the rest of the trip, he drove at 90 km/h. How far did he drive at each speed? I have to put it in linear equations. I think it is x+y= 470 and 100x+90y= 470 The answer is 200 at 100 km/h and 270 at 90 km/h. But how do I get those numbers, by using substitution???????