Question 44696
900x^2 - 8,100x = 1,800 

Divide both sides by 900 to get:
x^2-9x=2
x^2-9x-2=0

x=[9+sqrt(81+8)]/2 or x=[9-sqrt(90)]/2
Simplify a little to get:
x=[9+3sqrt10]/2 or x=[9-3sqrt(10)]/2

Cheers,
Stan H.