We will determine the number of pizza slices and nachos he bought as follows:
Here, p represents pizza slices and n nachos.
and:
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We solve the first function for either p or n:
And using this, we replace in the second function:
Now, we determine the value of n:
Now, we replace the value of n in the first equation and determine the value of p:
So, he bought 6 slices of pizza and 4 units of nachos.