2X ^ 2 + 2x-13 = 0 to solve the equation

2X ^ 2 + 2x-13 = 0 to solve the equation

2x^2+2x-13=0
x=[-2±√(4+104)]/4
=(-2±6√3)/4
=(-1±3√3)/2
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Solving equation (250-2x) (40-2x) = 450

Let 40-2x = y
The original equation is y * (210 + y) = 450
y^2+210y-450=0
Y = [- 210 ± radical (210 ^ 2 + 4 * 450)] / 2
=(- 210 ± root 690) / 2
X = y = (- 210 ± root 690) / 2x = (290 ± root 690) / 4
40-2x = y = (- 210 ± root 690) / 2
X = (290 ± root 690) / 4

Solution equation: 2x + X% = 40
Please be more detailed

2x+x%=40
2x+0.01x=40
2.01x=40
x=40÷2.01
x=4000/201
x≈19.90