展开 (x+y=18,6)(2x+4y=570)

解答

展开

(x + y = 18, 6) (2 x + 4 y = 570)

2 x^{2} + 4 x y = 570

求解步骤

(x + y = 18, 6) (2 x + 4 y = 570)

= (x + 18 \cdot 6 =, y) (2 x + 4 \cdot 570 = y)

使用 FOIL 方法:

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

a = x, b = y = 18, 6, c = 2 x, d = 4 y = 570

x \cdot 2 x + x \cdot 4 y = 570 + y = 18, 6 \cdot 2 x + y = 18, 6 \cdot 4 y = 570

2 xx + 4 x y = 570 + y = 18, 6 \cdot 2 x + y = 18, 6 \cdot 4 y = 570

乘开

2 xx + 4 x y : 2 x^{2} + 4 x y

2 x^{2} + 4 x y = 570

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