展开 ((x-1)2^{x+1})2.5

解答

展开

((x - 1) \cdot 2^{x + 1}) \cdot 2.5

2.5 \cdot 2^{x + 1} x - 2.5 \cdot 2^{x + 1}

求解步骤

((x - 1) \cdot 2^{x + 1}) \cdot 2.5

去除括号:

(a) = a

= (x - 1) \cdot 2^{x + 1} \cdot 2.5

= 2.5 \cdot 2^{x + 1} (x - 1)

使用分配律:

a (b - c) = ab - a c

a = 2^{x + 1} \cdot 2.5, b = x, c = 1

= 2^{x + 1} \cdot 2.5 x - 2^{x + 1} \cdot 2.5 \cdot 1

= 2.5 \cdot 2^{x + 1} x - 1 \cdot 2.5 \cdot 2^{x + 1}

数字相乘:

1 \cdot 2.5 = 2.5

= 2.5 \cdot 2^{x + 1} x - 2.5 \cdot 2^{x + 1}

e x p an d (- 1, - 3) y (2, - 2)

e x p an d so l v e (3 x^{2} + 6 x = 0)

e x p an d \frac{( m - n ) ^{2} + 6 ( m - n )}{9}

e x p an d \frac{2}{s ^{3} ( s + 1 )}

e x p an d \frac{e ^{- m}}{( 1 + e ^{- m} ) ^{2}}