Hello :)
So we are given Miguel bikes 25 km per hour.
Since it is per hour you can take a letter variable (in this case they used t) and multiply it by 25.
Then we are given the fact that he starts at mile 10, we would add this too the 25t because it is where he starts.
So Miguel's system of equations would be; d=25t+10
Now, for gabby we are given the fact that she bikes 30 km per hour. We do the same thing that we did with Miguel we take that number (30) and multiply it by a variable.
then we are given that she starts at 0, so we don't have to include this number.
So Gabby's system of equations would be; d=30t
the answer here would be A
Hope this helps :)
