展开 ((10+y)(y+2))/2

解答

展开

\frac{( 10 + y ) ( y + 2 )}{2}

\frac{y ^{2}}{2} + 6 y + 10

求解步骤

\frac{( 10 + y ) ( y + 2 )}{2}

乘开

(10 + y) (y + 2) : 12 y + y^{2} + 20

= \frac{12 y + y ^{2} + 20}{2}

使用分式法则:

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

\frac{12 y + y ^{2} + 20}{2} = \frac{12 y}{2} + \frac{y ^{2}}{2} + \frac{20}{2}

= \frac{12 y}{2} + \frac{y ^{2}}{2} + \frac{20}{2}

数字相除:

\frac{12}{2} = 6

= 6 y + \frac{y ^{2}}{2} + \frac{20}{2}

数字相除:

\frac{20}{2} = 10

= 6 y + \frac{y ^{2}}{2} + 10

改写为标准形式

= \frac{y ^{2}}{2} + 6 y + 10

e x p an d 4 e^{x^{2}} x (e^{x^{2}} + e^{- y^{2}})

e x p an d \frac{cos ^{3} ( n ) ( n + 1 )}{n ^{3}}

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

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

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