In 1990, the cost of tuition at a large Midwestern university was $100 per credit hour. In 2000, tuition had risen to $200 per credit hour

Question

Determine a linear function C(x) to represent the cost of tuition as a function of x, the number of years since 1990.		C(x)= ​
In the year 2007, tuition will be $  per credit hour.
In the year , tuition will be $370 per credit hour

Answer 1

$100 in 1990

$200 in 2000

C(x) = 100 + 10x where x = years since 1990

C(10) = 100+10(10) = $200 in 1990+10= 2000

in the year 2007, x = 2007-1990 = 17

C(17) = 100+10(17) = 100+170 = $270 in 2007

370=100 + 10x

10x = 370-100 = 270

x = 270/10 = 27 means the year 1990+27 = 2017

tuition increases $10 per year starting at $100 in 1990

in 10 years tutition goes from 100 to 10(10) = $200 in 2000

in 17 years tuition goes from 100 to 10(17) = $270 in 2007

in 27 years tuition goes from 100 to 10(27) = $370 in 2017

in x years tuition goes from 100 to 10x = $100+$10x in 1990+x years