Simplify this expression 4(1-2b)+7b-10

4(1-2b)+7b-10

mutiply the bracket by 4

(4)(1)= 4

(4)(-2b)=-8b

4-8b+7b-10 ( combine like terms)

4-10-8b+7b

-6-b or -b-6

-6-b or -b-6

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