展开 \binom{20}{15}2^{15}

解答

展开

(15 20) 2^{15}

\frac{131072}{3}

十进制

43690.66666 \dots

求解步骤

(15 20) \cdot 2^{15}

分式相乘:

a \cdot \frac{b}{c} = \frac{a \cdot b}{c}

= \frac{20 \cdot 2 ^{15}}{15}

约分:

5

= \frac{2 ^{15} \cdot 4}{3}

2^{15} \cdot 4 = 131072

= \frac{131072}{3}

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

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

e x p an d \frac{x ^{2} + 6 x + 5}{( x - 2 ) ( x ^{2} + x + 1 )}

e x p an d \frac{5 ( x ^{2} + 2 ) ^{4}}{2 x}

e x p an d \frac{n ( n + 1 ) ( 2 + n ^{2} + n )}{8} + \frac{n ( n + 1 )}{2}