展开 (7x+10=1,4)(x-2y=10)

解答

展开

(7 x + 10 = 1, 4) (x - 2 y = 10)

7 x^{2} - 14 x y = 10

求解步骤

(7 x + 10 = 1, 4) (x - 2 y = 10)

= (7 x + 10 \cdot 1 \cdot 4 =,) (x - 2 \cdot 10 = y)

使用 FOIL 方法:

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

a = 7 x, b = 10 = 1, 4, c = x, d = - 2 y = 10

7 xx + 7 x (- 2 y = 10) + 10 = 1, 4 x + 10 = 1, 4 (- 2 y = 10)

使用加减运算法则

+ (- a) = - a

7 xx - 7 \cdot 2 x y = 10 + 10 = 1, 4 x - 10 = 1, 4 \cdot 2 y = 10

乘开

7 xx - 7 \cdot 2 x y : 7 x^{2} - 14 x y

7 x^{2} - 14 x y = 10

e x p an d 2 (π x^{4} - π x)

e x p an d (- d + 2 (\frac{84}{d}) - 2 = 0) d

e x p an d y (1 + ln (x y) + 2 x) d x + (x - 2 y^{2}) d y

e x p an d lo g_{(x + 1) (x + 2)} (x)

e x p an d \frac{5}{s ( s + 2 ) ( 0.5 s + 1 )}