Question

$4 {x}^{3} - 40 {x}^{2} + 100x = 0$
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Answer 1

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${4x}^{3} - {40x}^{2} + 100x = 0 \\ 4x( {x}^{2} - 10x + 25) = 0 \\ 4x {(x - 5)}^{2} = 0 \\ x {(x - 5)}^{2} = 0 \\ x = 0 \: \: \: o \: \: \: {(x - 5)}^{2} = 0 \\ x = 0 \: \: \: o \: \: \: x - 5 = 0 \\ x = 0 \: \: \: o \: \: \: x = 5$