1. ## Linear Systems

hey,
i dont understand this question. I tried solve it but i got lost in the middle somewhere. Could you please help me with it, please?

Kareem took 5 hours to drive 470km from Sudbury to Brantford. For part of the trip, he drove at 100km/h. For the rest of the trip he drove at 90km/h. How far did he drive at each speed?

Kareem took 5 hours to drive 470km from Sudbury to Brantford.
For part of the trip, he drove at 100km/h. For the rest of the trip he drove at 90km/h.
How far did he drive at each speed?

Let $\displaystyle t$ = times he drove at 100 km/hr.
Then $\displaystyle 5-t$ = time he drove at 90 km/hr.

He drove $\displaystyle t$ hours at 100 klm/hr.
. . His distance was: .$\displaystyle 100t$ km.

He drove $\displaystyle 5-t$ hours at 90 km/hr.
. . His distance was: .$\displaystyle 90(5-t)$ km.

His total distance was 470 km.

There is our equation! . . . $\displaystyle 100t + 90(5-t) \:=\:470$

Can you finish it now?

3. ## linear systems

thank you.i get it from here=)