解方程:3+1/2+(450-3x)/(x+0.2)=450/x

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解方程:3+1/2+(450-3x)/(x+0.2)=450/x

3+1/2+(450-3x)/(x+0.2)=450/x
7/2+(450-3x)/(x+0.2)=450/x
(7/2)x(x+0.2)+(450-3x)x=450(x+0.2)
7/2x^2+7/10x+450x-3x^2=450x+90
1/2x^2+7/10x-90=0
5x^2+7X-900=0
x1=12.73 x2=14.135

3.5x^2+0.7x+450x-3x^2=450x+90
0.5x^2+0.7x-90=0
x^2+1.4x-180=0
(x+0.7)^2=180.49
x=-0.7加减根号180.49