Two students, Abby and Melissa go for a walk. Abby begins walking 30 seconds earlier than Melissa . -Abby walks at a speed of 8 feet per second.
-Melissa walks at a speed of 9 feet per second.

Abby had been walking for BLANK seconds when both students had walked exactly the same distance. (round to the nearest whole)
please help me

270 seconds

Step-by-step explanation:

Melissa's time = x seconds

Abby's time = (x + 30) seconds

Abby walks at a speed of 8 feet per second, and Melissa walks at a speed of 9 feet per seconds.

But, speed =

For Abby,

8 =

distance = 8(x + 30) ................. 1

for Melissa,

9 =

distance = 9x ............. 2

From equations 1 and 2, for the same distance;

8(x + 30) = 9x

8x + 240 = 9x

x = 240 seconds

Abby's time = (x + 30)

                    = (240 + 30)

                    = 270 seconds

So that Abby has been walking for 270 seconds when both students had walked exactly the same distance.