展开 ((5-sqrt(3))(5+2sqrt(3)))/2

解答

展开

\frac{( 5 - 3 ) ( 5 + 2 3 )}{2}

\frac{19}{2} + \frac{5 3}{2}

十进制

13.83012 \dots

求解步骤

\frac{( 5 - 3 ) ( 5 + 2 3 )}{2}

乘开

(5 - 3) (5 + 23) : 19 + 53

= \frac{19 + 5 3}{2}

使用分式法则:

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

\frac{19 + 5 3}{2} = \frac{19}{2} + \frac{5 3}{2}

= \frac{19}{2} + \frac{5 3}{2}

e x p an d (1 - c e^{3 x})^{2}

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e x p an d 3 (x + 1)^{2} - 3 (x - 1)^{2}

e x p an d \frac{( s + 9 - j ) ( s + 9 + j )}{( s - 8 - j ^{3} ) ( s - 8 + j ^{3} )}

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