College Math
posted by HM .
Sales at a computer retail store were $1,000,000 in 1982 and $1,790,000 in 1987
let x=0 represent 1982
find the equation giving year sales. estimate sales in 1990.
Could you guys help me with this.

sales=slope*time+constant
slope= 1.790/5
sales= 1.790/5 * (year1982)+1,000,000
year is in the format of like 1990
sales in 1990=1.790/6(19901982)+1000000 
For some reason this is not correct :/
It is not in one of the multiple choices