1/4+1/8+1/16+...
=1/4+1/8+1/16+1/32+1/64+1/128+1/256+1/512+1/1024+1/2048
=1/2-1/4+1/4-1/8+1/8-1/16+1/16-1/32+1/32-1/64+1/64-1/128+1/128-1/256+1/256-1/512+1/512-1/1024+1/1024-1/2048
=1/2-1/2048
=1024/2048-1/2048
=1023/2048
tinh a = 1/2 + 1/4 + 1/8 + 1/16 + ... (biet tong tren co 10 so hang)
A = 1/4 + 1/2 + 1/8 + 1/16 + ...( tong co 10 so hang )
tinh a=1/2+1/4+1/8+1/16+.....(tong co 10so hang)
a=...(viet phan so toi gian)
tim a biet a=1/2+1/4+1/8+1/16+....[tong co 10 so hang]
tinh tong 2+4+6+8...... biet tong do co 60 so hang tong cua 60 so hang la bao nhieu
Tinh tong M:
M = 1/4+ 1/28 + 1/70 +1/130 + ...... ( Biet tong M co 30 so hang )
tinh tong 2-4-6+8+....bet tong co 60 so hang
Tinh tong A=1+4+7+10+....+x biet x la so hang thu 2016 cua tong
A bang 1/2 cong 1/4 cong 1 /8 cong 1/16 ... co 10 so hang hay tim A