330=50+40t

280=40t

t=7 hours

=)

For the speed, it becomes…

i=s-at

Plug in any numbers that you have…

C = 50 + 40t

We’re trying to isolate the ‘t’. By the rules of precedence, we’d multiply 40 times t first, then add 50. To isolate t, we have to undo those in reverse order.

Last would be to add 50, so the first thing we’ll do is subtract 50 from both sides:

C – 50 = 50 + 40t – 50

C – 50 = 40t

Now we have to undo the “multiply by 40”. We undo multiplication by division:

(C – 50)/40 = 40t/40 = t

So,

t = (C – 50)/40

If the cost is 330, we just plug that in for C:

t = (330 – 50)/40 = 280/40 = 7

So he worked seven hours.

Go, now, and do thou likewise.

C-50=40t

t=(c-50)/40

b) t=(330-50)/40

t= 280/40

t= 7 hours

a) s=i+at

i=s-at

b) i=100-(60)(1)

i= 40 mph