展开 (21)/(x(x^2+7))

解答

展开

\frac{21}{x ( x ^{2} + 7 )}

\frac{21}{x ^{3} + 7 x}

求解步骤

\frac{21}{x ( x ^{2} + 7 )}

乘开

x (x^{2} + 7) : x^{3} + 7 x

= \frac{21}{x ^{3} + 7 x}

e x p an d A (- 31) y B (- 2, - 4)

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