Beth ran a 400 meter
dash in 57.2 seconds.
this was 2.4 sec
faster than her
previous time. what
was her previous
time?
(with equation)

So if Beth ran the 400 meter dash in 57.2 seconds, and that time was 2.4 seconds faster than her previous time, she would have run a 59.6 second previous time. The equation would be X (current time) + Y (time difference) = Z (Previous time) we can see that her current time is 57.2 seconds, so that would replace X. We now have 57.2+Y=Z. So we can see in the problem that it was 2.4 seconds faster, so that’s the time difference. Our new equation is 57.2+2.4=Z. Now all we have to do is add 57.2 and 2.4 and you get her previous time, which is 59.6 seconds. Hope this helped! :D