展开 (9x^2-7a^2)left(9x^2+7a^2)

解答

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(9 x^{2} - 7 a^{2}) l e f t (9 x^{2} + 7 a^{2})

81 e l x^{4} f t - 49 e l a^{4} f t

求解步骤

(9 x^{2} - 7 a^{2}) l e f t (9 x^{2} + 7 a^{2})

= e l f t (9 x^{2} - 7 a^{2}) (9 x^{2} + 7 a^{2})

乘开

(9 x^{2} - 7 a^{2}) (9 x^{2} + 7 a^{2}) : 81 x^{4} - 49 a^{4}

= l e f t (81 x^{4} - 49 a^{4})

乘开

l e f t (81 x^{4} - 49 a^{4}) : 81 e l x^{4} f t - 49 e l a^{4} f t

= 81 e l x^{4} f t - 49 e l a^{4} f t

e x p an d (r - 11 - 13)^{2}

e x p an d \frac{x ^{4} + 10 x ^{3} + 23 x ^{2} + 14 x}{4}

e x p an d \frac{5 - x}{( x + 6 ) ( x ^{2} + 1 )}

s im pl i f y (\frac{2 x ^{2} y ^{2}}{3} + 2) (x y + 4 x)

e x p an d \frac{d}{d x} ((x - 1) (x - 7)^{3}) + 10