Answer: [tex]C=270x+2200[/tex]
Step-by-step explanation:
Given
Cost per student in the year 1978 is $2200
The cost increases to $10,300 in 2008
Suppose [tex]C=mx+a[/tex] is the linear equation defining the cost per student after x years
Substitute the value for 1978
[tex]\Rightarrow 2200=m(0)+c\\\Rightarrow c=2200[/tex]
After 30 years it becomes
[tex]\Rightarrow 10,300=m(30)+2200\\\Rightarrow 30m=8100\\\Rightarrow m=270[/tex]
Thus, the linear equation becomes
[tex]\Rightarrow C=270x+2200[/tex]