First subtract the number of free checks from the total number

10-4=6

multiply that by the cost of each check 6 x .75=$4.50

Then add the monthly service charge

4.50+2.50=$7.00

The full problem can be written out:

(10-4)(.75)+2.5

6(.75)+2.5

4.5+2.5

7

She gets 4 free checks, so you have to chuck off (subtract) 4 from the 10 she writes during the month–that means she pays for 6 checks times .75 = $4.50.

So with $2.50 + $4.50, she would pay $7.00 on the Budget Plan.

She writes 10 checks-and 4 are free, so 6 are not free.

6 times $0.75 equals $4.50. 2.50+4.50=7$, the amount she will be charged.