展开 (3f+2g=5,)(f-g=1)

解答

展开

(3 f + 2 g = 5,) (f - g = 1)

3 f^{2} - 3 g f = 1

求解步骤

(3 f + 2 g = 5,) (f - g = 1)

= (3 f + 2 \cdot 5 =, g) (f - 1 = g)

使用 FOIL 方法:

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

a = 3 f, b = 2 g = 5,, c = f, d = - g = 1

3 ff + 3 f (- g = 1) + 2 g = 5, f + 2 g = 5, (- g = 1)

使用加减运算法则

+ (- a) = - a

3 ff - 3 g f = 1 + 2 g = 5, f - 2 g = 5, g = 1

乘开

3 ff - 3 g f : 3 f^{2} - 3 g f

3 f^{2} - 3 g f = 1

e x p an d (4 x - 5, x^{2} + 4) (x)

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

e x p an d - 4 b (- 2 b e^{2} - 4)

e x p an d \frac{3}{( x + 5 ) ^{3}}

e x p an d \frac{2}{( 1 - x ) ( 2 - x )}