thuc hien phep tinh :M=1+1/2(1+2)+1/3(1+2+3)+1/4(1+2+3+4)+...+1/16(1+2+3+...+16)
thuc hien phep tinh (1-1/(1+2)).(1-1/(1+2+3))...(1-1/(1+2+3+...+2006))
Thuc hien phep tinh:
B=1/3+1/3^2+1/3^3+...+1/3^2004+1/3^2005
tim x biet,
5x + 5x+2= 650
Thuc hien phep tinh
(1+2+3+4+...+90).(12.34 - 6.68) : (1/3+1/4+1/5+1/6)
thuc hien phep tinh (Tinh nhanh neu co the)
(-5/12+7/4-3/8)-|4 va 1/2 -7 va 1/2|-( 1/4-5/2)
a;1/2-1/3.7-1/7.11-1/11.15 -1/15.19-1/19.23-1/23.27 thuc hien phep tinh
thuc hien phep tinh 1/100x99 - 1/99x98 - ........- 1/3x2 - 1/2x1
Thuc hien phep tinh
\(A=\left(1-\frac{1}{1+2}\right).\left(1-\frac{1}{1+2+3}\right)....\left(1-\frac{1}{1+2+3+...+2006}\right)\)
Thuc hien phep tinh:
\(P=\left(1-\frac{1}{1+2}\right).\left(1-\frac{1}{1+2+3}\right)...\left(1-\frac{1}{1+2+3+4+...+2011}\right)\)
Ai trả lời nhanh và đúng nhất tôi sẽ tích cho.