tính nhanh :
4/1x3x5 + 4/3x5x7 + 4/5x7x9 + 4/7x9x11 + 4/9x11x13 .
4/1x3x5 + 4/3x5x7 + 4/5x7x9 + 4/7x9x11 + 4/9x11x13 . Tính nhanh nhé
4/1x3x5 + 4/3x5x7 + 4/5x7x9 + 4/7x9x11 + 4/9x11x13
tính nhanh :
4/1x3x5 + 4/3x5x7 + 4/5x7x9 + 4/ 7x9x11 + 4/9x11x13
\(\dfrac{4}{1x3x5}+\dfrac{4}{3x5x7}+\dfrac{4}{5x7x9}+\dfrac{4}{9x11x13}\)
4/1x3x5 + 4/3x5x7 + 4/5x7x9 + 4/7x9x11 + 4/9x11x13
2.1991/1990 x 1992/1991 x 1993/1992 x 1994/1993 x 1995/997
ai lam dung minh tick
Cho
A=4/3x5x1+4/3x5x7+4/5x7x9+4/7x9x11+4/9x11x13
Ai tính đc tik cho
Tính nhanh các biểu thức sau:
a,2/1x3x5+2/3x5x7+2/5x7x9+2/7x9x11
b,1/1x2x3+1/2x3x4+1/3x4x5+1/4x5x6
Tính các biểu thức sau
a,2/1x3x5+2/3x5x7+2/5x7x9+2/7x9x11
b,1/1x2x3+1/2x3x4+1/3x4x5+1/4x5x6