展开 (2x+3y=0,)(3x-y=2)

解答

展开

(2 x + 3 y = 0,) (3 x - y = 2)

6 x^{2} - 2 x y = 2

求解步骤

(2 x + 3 y = 0,) (3 x - y = 2)

= (2 x + 3 \cdot 0 =, y) (3 x - 2 = y)

使用 FOIL 方法:

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

a = 2 x, b = 3 y = 0,, c = 3 x, d = - y = 2

2 x \cdot 3 x + 2 x (- y = 2) + 3 y = 0, 3 x + 3 y = 0, (- y = 2)

使用加减运算法则

+ (- a) = - a

2 \cdot 3 xx - 2 x y = 2 + 3 y = 0, 3 x - 3 y = 0, y = 2

乘开

2 \cdot 3 xx - 2 x y : 6 x^{2} - 2 x y

6 x^{2} - 2 x y = 2

e x p an d (2 x + y) d x + x (1 - x - y) d y

e x p an d 4 \cdot (1 - \frac{1}{e ^{x}})

e x p an d (1 - e^{- t}) u (t)

e x p an d \frac{3 ( x - 2 )}{- 2 x + 7}

e x p an d \frac{( x + 3 ) ^{2}}{3}