因式分解 25z^2+30z+9

解答

因式分解

25 z^{2} + 30 z + 9

(5 z + 3)^{2}

求解步骤

25 z^{2} + 30 z + 9

改写为形式

a^{2} + 2 ab + b^{2} :

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

9 = 3^{2}

30 z = 2 \cdot 5 z \cdot 3

= (5 z)^{2} + 2 \cdot 5 z \cdot 3 + 3^{2}

使用完全平方公式:

a^{2} + 2 ab + b^{2} = (a + b)^{2}

(5 z)^{2} + 2 \cdot 5 z \cdot 3 + 3^{2} = (5 z + 3)^{2}

= (5 z + 3)^{2}

x^{3} + 3 x^{2} - 10 x = 30

7 x^{2} - 3 = 60

f a c t or 16 m^{2} - 40 m + 25

p + 5 \geq - 12

3 x - 7 = 7 x + 13