展开 (2x-3)(4x^2-6x=9)

解答

展开

(2 x - 3) (4 x^{2} - 6 x = 9)

8 x^{3} - 12 x^{2} = 9

求解步骤

(2 x - 3) (4 x^{2} - 6 x = 9)

= (2 x - 3) (4 x^{2} - 6 \cdot 9 = x)

使用 FOIL 方法:

(a + b) (c + d) = a c + a d + b c + b d

a = 2 x, b = - 3, c = 4 x^{2}, d = - 6 x = 9

= 2 x \cdot 4 x^{2} + 2 x (- 6 x = 9) + (- 3) \cdot 4 x^{2} + (- 3) (- 6 x = 9)

使用加减运算法则

+ (- a) = - a, (- a) (- b) = ab

2 \cdot 4 x^{2} x - 2 \cdot 6 xx = 9 - 3 \cdot 4 x^{2} + 3 \cdot 6 x = 9

乘开

2 \cdot 4 x^{2} x - 2 \cdot 6 xx : 8 x^{3} - 12 x^{2}

8 x^{3} - 12 x^{2} = 9

e x p an d \frac{3}{( x - 1 ) \cdot ( x - 8 )}

e x p an d \frac{7 x ( 5 x + 7 )}{( 7 x - 5 ) ^{2}}

e x p an d \frac{4}{( s + 4 ) ( s - 4 )}

e x p an d (e^{5} + q)^{2}

e x p an d \frac{2 ( 601 - 26 )}{15}