展开 (pi(r+3)^2)-(pi*r^2)

解答

展开

(π (r + 3)^{2}) - (π \cdot r^{2})

6 π r + 9 π

求解步骤

(π (r + 3)^{2}) - (π r^{2})

去除括号:

(a) = a

= π (r + 3)^{2} - π r^{2}

(r + 3)^{2} = r^{2} + 6 r + 9

= π (r^{2} + 6 r + 9) - π r^{2}

乘开

π (r^{2} + 6 r + 9) : π r^{2} + 6 π r + 9 π

= π r^{2} + 6 π r + 9 π - π r^{2}

化简

π r^{2} + 6 π r + 9 π - π r^{2} : 6 π r + 9 π

= 6 π r + 9 π

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

e x p an d \frac{( + 4 s ^{2} - 3 s - 1 ) ( 2 s + 2 )}{s}

e x p an d \frac{( π \cdot ( 3 \cdot x - 3 x ) )}{3}

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

e x p an d (x + 2) (\frac{22}{x} + 2)