Answer:
Anthony bought 7 markers.
Explanation:
Hi, so in this problem we will need 2 equations! One to represent the unknown numbers of pens and markers, and the other to represent the prices of the pens and markers.
Our first equation should look like:
12 = p + m
12 represents the total number of items purchased, p is the letter for pens, and m is the letter for markers, as the number of each is unknown.
Next, the other equation shoud look like this:
2.80 = 0.35 p + 0.15 m
This is because the total price is 2.80 and the pens cost 35 cents each, and each marker costs 15 cents.
Now, we need to plug one of the equations into the other to figure out the variable for the marker. Let's change the 12 = p +m equation, so that the variable p is isolated.
The equation should now look like this: P = 12 - m.
Now, let's plug this equation into the p variable for the 2.80 = 0.35p + 0.15m.
It should look like this: 2.80 = 0.35(12 - m) + 0.15 m
Now, let's distribute! :)
The equation should now be distributed as such:
2.80 = 4.2 - 0.35 m + 0.15 m.
Now, let's simplify the equation!
-1.4 = -0.2 m
Now, all that's left is to divide the -1.4 by the -0.2.
You should get 7, which is the total number of markers Anthony bought!
Hope this helps!