(a-b)-(4a+3c)-(c-2a) full process please

-a - b - 4c

Step-by-step explanation:

(a  - b)  -  (4a + 3c) - (c - 2a) = a - b - 4a - 3c - c + 2a

                                            = a - 4a + 2a  - b  - 3c - c  {Combine like terms}

                                            = -a - b - 4c

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m