展开 (2x+3y=7,)(6x-y=1)

解答

展开

(2 x + 3 y = 7,) (6 x - y = 1)

12 x^{2} - 2 x y = 1

求解步骤

(2 x + 3 y = 7,) (6 x - y = 1)

= (2 x + 3 \cdot 7 =, y) (6 x - 1 = y)

使用 FOIL 方法:

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

a = 2 x, b = 3 y = 7,, c = 6 x, d = - y = 1

2 x \cdot 6 x + 2 x (- y = 1) + 3 y = 7, 6 x + 3 y = 7, (- y = 1)

使用加减运算法则

+ (- a) = - a

2 \cdot 6 xx - 2 x y = 1 + 3 y = 7, 6 x - 3 y = 7, y = 1

乘开

2 \cdot 6 xx - 2 x y : 12 x^{2} - 2 x y

12 x^{2} - 2 x y = 1

e x p an d (1 + 5) e^{4}

e x p an d 4 (2 x + 3 y = 53)

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

e x p an d e^{7 x - 9} d (7 x - 9)

e x p an d (d - 2) (e + 3) (f + 2)