展开-3(6x+2y=140)

解答

展开

- 3 (6 x + 2 y = 140)

- 18 x - 6 y = 140

求解步骤

- 3 (6 x + 2 y = 140)

= - 3 (6 x + 2 \cdot 140 = y)

使用分配律:

a (b + c) = ab + a c

a = - 3, b = 6 x, c = 2 y = 140

- 3 \cdot 6 x + (- 3) \cdot 2 y = 140

使用加减运算法则

+ (- a) = - a

- 3 \cdot 6 x - 3 \cdot 2 y = 140

乘开

- 3 \cdot 6 x - 3 \cdot 2 y : - 18 x - 6 y

- 18 x - 6 y = 140

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e x p an d \frac{12 x ( - 2 x ^{8} - 7 x ^{4} - 1 )}{( x ^{4} - 1 ) ^{\frac{7}{2}}}

e x p an d (e^{5 x} + e^{- 5 x})^{2}

e x p an d 3 \frac{25 ( 2 - i )}{3 + 4 i} + ki

e x p an d (\frac{2 a - 1}{b})^{4}