P(n)=0.80n+5.50

There is no question here.

You have to get the variables by themselves to solve this. Even so, "p(n)" is a variant of "f(x)" and can be replaced with "y" to make it simpler. y = 0.80n + 5.50. Subtract the constant. y + 5.50 = 0.80n. Then divide the "0.80" from the "n" to get the "n" alone.