展开 (acx^2-by)(cx+dy)

解答

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(a c x^{2} - b y) (c x + d y)

a c^{2} x^{3} + a c x^{2} d y - c b x y - b y d y

求解步骤

(a c x^{2} - b y) (c x + d y)

使用 FOIL 方法:

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

a = a c x^{2}, b = - b y, c = c x, d = d y

= a c x^{2} c x + a c x^{2} d y + (- b y) c x + (- b y) d y

使用加减运算法则

+ (- a) = - a

= a cc x^{2} x + a c x^{2} d y - c b x y - b y d y

a cc x^{2} x = a c^{2} x^{3}

= a c^{2} x^{3} + a c x^{2} d y - c b x y - b y d y

e x p an d (x tan (\frac{y}{x}) + y) d x - x d y

e x p an d, (x + 1) (x - 7)

e x p an d - 5 (- 3 s = 9 s + 9) - 2 s

e x p an d (1 - v) (4 + v) d x

e x p an d (2 x + sin (3 x)) d x