Question 980457
{{{-0.0004x^2+60x=220000}}}


{{{x^2-(60/0.0004)x+220000/(0.0004)=0}}}


{{{x^2-15000x+550000000=0}}}


{{{x=(1500+- sqrt(1500^2-4*550000000))/(2)}}}


{{{x=(1500+- sqrt(2200001500))/2}}}


{{{x=(1500+- sqrt(2^2*5^3*37*109*1091))/2}}}


{{{x=2*750/2+- 2*sqrt(5^3*37*109*1091)/2}}}


{{{x=750+- sqrt(5^3*37*109*1091)}}}


You want the PLUS form.
{{{x=23452.0+750}}}
{{{highlight(x=24202)}}} but you would likely not want as much as five significant figures; you would want less, maybe three.