algebra
posted by Nick .
For 1983 through 1995, the amount of private donations D (in millions) allocated to education can be modeled by
D= 1.78t^36.02t^2+ 752t+ 6701
where t is the number of years since 1983. In what year was 14.3 billion of private donations allocated to education?
(My main problems were location the real zeros on the Ti84 graphing calculator of which I could only find one line on the graph. Also I'm not sure if when I subtract 6701 from 14.3 billion if I am suppose to move the decimal back one for remaining numbers. Ex. being 1.78t^3 to 0.178t^3.)
Thanks in advance.

chndt