因式分解 81a^2-25b^2

解答

因式分解

81 a^{2} - 25 b^{2}

(9 a + 5 b) (9 a - 5 b)

求解步骤

81 a^{2} - 25 b^{2}

81 a^{2} = (9 a)^{2}

25 b^{2} = (5 b)^{2}

= (9 a)^{2} - (5 b)^{2}

使用平方差公式:

x^{2} - y^{2} = (x + y) (x - y)

(9 a)^{2} - (5 b)^{2} = (9 a + 5 b) (9 a - 5 b)

= (9 a + 5 b) (9 a - 5 b)

s im pl i f y - 1 x - 22 x^{2} - 5400

f a c t or x^{4} \cdot y - x^{2} \cdot y^{2} + x^{2} \cdot y

f a c t or 5 x^{2} \cdot y + 8 x^{2} \cdot y^{2} + 3 y

s im pl i f y (64 p^{3})^{\frac{4}{3}}

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