For this case we must solve the following system of equations:

We multiply the first equation by -2:

We add the new equation with the second one:

We have different signs subtracted and the sign of the major is placed:

Now we find the value of the variable "y":

Thus, the solution of the system is given by:

Answer:

She will have to pay $2,700.
She is starting with a bill of $11,000. If we subtract the 1500 grant and 5000 scholarship, she has left a bill of 4500.
She is going to earn 40% of it, so she still have to pay 60% of it.
0.6 x 4500 = 2700
She washed 30 plates from 7:30 to 7:35.....so she washed 30 plates in 5 minutes.....30/5 = 6 plates per minute
so if she started washing plates at 7:15 and ended at 7:38...how many plates did she wash....
from 7:15 to 7:38 is 23 minutes...and if she can wash 6 plates per minute, then in 23 minutes, she can wash (23 * 6) = 138 plates <==
the equation...
y = -6x + b...with b being the number of plates she started with and x being the number of minutes and y being the plates she has left to wash...I am not 100% sure on this equation...I am so sorry
-6W=-A
6W=A
W=A/6 is the answer your looking for
Hope this helped!
4/6=66.67%
5/8=62.5%
Therfore 4/6 is bigger than 5/8