Question

math question down below

Answer 1

The total cost, 'C' is the sum of the cost of the notebooks, 'n' and the cost of the pencils. 'p':
$C=n+p$

The notebooks cost $2.55 each so for 4 notebooks we have:
$n=4 \times \ 2.55$

The cases of pencils cost $1.99 each so for 3 cases we have:
$p=3 \times 1.99$

Substituting into our main equation we have:
$C=n+p$
$C=4(2.55)+3(1.99)$
$C=10.20+5.97$
$C=16.17$

Now that we know the total cost we can find the amount of change by subtraction from the total amount she has:
$Change=Total-Cost$
$Change=\ 20.00-\ 16.17$
$Change=\ 3.83$