print shop chain

Question

Two young college graduates opened a chain of print shops. The chain expanded rapidly during the early 1990s and many new stores were opened. The number of print shops in operation during any year from 1990 to 2005 is given by the equation
y=−2.5x2+17.5x+129
where x is the number of years since 1990. How many print shops where there in
1993??

Answer 1

Sine 1993 is 3 years after 3, x = 3

 

y = 2.5x²+17.5x+129 = 204 print shops in 1993

Answer 2

So if for the year 1990, x = 0

(this can be seen that in 1990 y=129)

for 1993, plug 3 in for x

 y= -2.5 (3)^2 +17.5(3) + 129

 = ?