展开 (a(1-r))/(r+1)

解答

展开

\frac{a ( 1 - r )}{r + 1}

\frac{a - a r}{r + 1}

求解步骤

\frac{a ( 1 - r )}{r + 1}

乘开

a (1 - r) : a - a r

= \frac{a - a r}{r + 1}

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

e x p an d 1 + \frac{1}{2}

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

e x p an d \frac{n + 2}{( n + 3 ) ^{2}}

e x p an d (7 x + 8 y = 29, 0) (5 x + 11 y = 2600)