展开 (7(sqrt(13)+2))/9

解答

展开

\frac{7 ( 13 + 2 )}{9}

\frac{7 13}{9} + \frac{14}{9}

十进制

4.35987 \dots

求解步骤

\frac{7 ( 13 + 2 )}{9}

乘开

7 (13 + 2) : 713 + 14

= \frac{7 13 + 14}{9}

使用分式法则:

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

\frac{7 13 + 14}{9} = \frac{7 13}{9} + \frac{14}{9}

= \frac{7 13}{9} + \frac{14}{9}

e x p an d (x y - x + y - 1) d x - (x y + x) d y

e x p an d 2 (5 x + 2 y = 16)

e x p an d - 2 (5 + 6 m + 16 = - 90)

s im pl i f y \frac{1}{2} (e^{i x} + e^{- i x})

e x p an d \frac{a}{( a + b ) + b ( a + b )}