Answer:
The year is 2008
Step-by-step explanation:
Acording to the formula: 
 
1,070 = 6t2 + 3t + 440 
 0 = 6t2 + 3t + 440 – 1,070 
 0 = 6t2 + 3t – 630 
This is a quadratic function and we must solve the roots. 
x=(-b±√(b^2-4ac))/2a 
Where: 
x = t (number of years since 1998) 
a = 6 
b = 3 
c = - 630 
 
t=(-3±√(3^2-4*6*(-630)))/(2*6) 
t1 = 10 
t2 = -10.5 
Since a negative value is illogical, we take the positive root (t = 10). So the result is the year 2008 (1998 + 10 years).