Respuesta :

Answer: Paco bought 7 markers and 8 pencils.

Step-by-step explanation:

Let's define the variables:

P = number of pencils that Paco bought

M = number of markers that Paco bought.

We know that P + M  = 15.

We also know that each pencil costs $0.30 and each marker costs $1.25, and the total price for the whole purchase is $11.15

Then:

P*$0.30 + M*$1.25 = $11.15

Then we have the system of equations:

P + M  = 15

P*$0.30 + M*$1.25 = $11.15

To solve this, we can start by isolating one of the variables in the first equation, let's isolate P.

P = 15 - M

Now we can replace this in the second equation to get:

(15 - M)*$0.30 + M*$1.25 = $11.15

$4.50 - M*$0.30 + M*$1.25 = $11.15

$4.50 + M*$0.95 = $11.15

M*$0.95 = $11.15 - $4.50 = $6.65

M = $6.65/$0.95 = 7

Then paco bough 7 markers, and we can find the number of pencisl by the equation:

P + M = 15

P = 15 - M = 15 - 7 = 8

Then Paco bought 7 markers and 8 pencils.