展开 (3x-4y=4,1)(11x+6y=47)

解答

展开

(3 x - 4 y = 4, 1) (11 x + 6 y = 47)

33 x^{2} + 18 x y = 47

求解步骤

(3 x - 4 y = 4, 1) (11 x + 6 y = 47)

= (3 x - 4 \cdot 4 \cdot 1 =, y) (11 x + 6 \cdot 47 = y)

使用 FOIL 方法:

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

a = 3 x, b = - 4 y = 4, 1, c = 11 x, d = 6 y = 47

3 x \cdot 11 x + 3 x \cdot 6 y = 47 + (- 4 y = 4, 1) \cdot 11 x + (- 4 y = 4, 1) \cdot 6 y = 47

使用加减运算法则

+ (- a) = - a

3 \cdot 11 xx + 3 \cdot 6 x y = 47 - 4 y = 4, 1 \cdot 11 x - 4 y = 4, 1 \cdot 6 y = 47

乘开

3 \cdot 11 xx + 3 \cdot 6 x y : 33 x^{2} + 18 x y

33 x^{2} + 18 x y = 47

e x p an d - 2 x + 4 + 5 x - 8

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

e x p an d 2 (x - \frac{π}{3})

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

e x p an d - 3 π (32 - 11)