A business shipped 90 packages one day. Customers are charged $4.50 for each standard-delivery package and $9.50 for each express-delivery package. Total shipping charges for the day were $555.00. How many of each kind of package were shipped?

number of standard-delivery package x = 60

number of express-delivery package y = 30

Step-by-step explanation:

We have:

Total number of packages shipped one day = 90

Total shipping chages for the day = 555 $

Charged for each standard-delivery package = 4.5 $

Charge for each express-delivery package = 9.5 $

Let call x number of standard-delivery package. and

y number of express-delivery package.

Then x + y = 90

And 4.5 * x + 9.5 * y = 555

we get a 2 equation system, solving

y = 90 - x

4.5*x + 9.5 * (90 - x) = 555

4.5*x + 855 - 9.5*x = 555

- 5*x = - 855 + 555

5*x = 300

x = 60

And then y = 90 - 60

y = 30