展开 (3(5+sqrt(85)))/5

解答

展开

\frac{3 ( 5 + 85 )}{5}

3 + \frac{3 17}{5}

十进制

8.53172 \dots

求解步骤

\frac{3 ( 5 + 85 )}{5}

乘开

3 (5 + 85) : 15 + 385

= \frac{15 + 3 85}{5}

使用分式法则:

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

\frac{15 + 3 85}{5} = \frac{15}{5} + \frac{3 85}{5}

= \frac{15}{5} + \frac{3 85}{5}

数字相除:

\frac{15}{5} = 3

= 3 + \frac{3 85}{5}

消掉

\frac{3 85}{5} : \frac{3 17}{5}

= 3 + \frac{3 17}{5}

e x p an d (2 x - 1) - (6 x)

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

e x p an d 2 aaabbbb \cdot (a) b

e x p an d - 7 (6 - 2 (3 - 5 x) = 10 x)

e x p an d (3 x + 1) \circ \cdot 3^{x + 1}