展开-(2(4sqrt(2)-5))/7

解答

展开

- \frac{2 ( 4 2 - 5 )}{7}

- \frac{8 2}{7} + \frac{10}{7}

十进制

- 0.18767 \dots

求解步骤

- \frac{2 ( 4 2 - 5 )}{7}

乘开

2 (42 - 5) : 82 - 10

= - \frac{8 2 - 10}{7}

使用分式法则:

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

\frac{8 2 - 10}{7} = - (\frac{8 2}{7}) - (- \frac{10}{7})

= - (\frac{8 2}{7}) - (- \frac{10}{7})

去除括号:

(a) = a, - (- a) = a

= - \frac{8 2}{7} + \frac{10}{7}

e x p an d \frac{3 π}{2} (\frac{5 csc ( θ ) - 3 cot ( θ )}{r} + 3)

e x p an d 2 t + (e^{- 3 t} - 2 t) θ (t - 5)

e x p an d e^{3 x} (2 x + y^{2} + 3 y)

e x p an d \frac{ln ( 4 n )}{ln ( 4 ( n + 1 ) )}

e x p an d \frac{x ^{4} - 5 x ^{3} + 6 x ^{2} + 4 x - 8}{x + 1}