2/15+2/35+2/63+2/99+2/143
2/35+2/63+2/99+2/143 = ?
a ) A = 1/3 + 1/15 + 1/35 + 1/63 + 1/99 + 1/143
b) x + ( x + 1 ) + ( x + 2 ) + ....+ ( x + 99 ) = 14950
éc ô éc
Tính nhanh tổng sau\(\frac{2^2}{15}+\frac{2^2}{35}+\frac{2^2}{63}+\frac{2^2}{99}+\frac{2^2}{143}\)
jup mik nha
Tính tổng:
1/15+1/35+1/63+1/99+1/143
1/5*9+1/9.13+1/13*17+...+1/25*29
2/15+3/15+2/63+...+2/9603
mơn mọi người
a) A = 1/15+1/35+1/63+1/99+1/143+1/195
a) M= 1+3+3^2+3^3+...+3^25 và N = 3^26 : 2 Tính N-M
1 Tính nhanh:
a. 1/15+1/35+1/63+1/99+1/143
b. 1/2+1/14+1/35+1/65+1/104+1/152
2 Chứng minh: D=(1/2)^2 +(1/3)^2 +(1/4)^2 +....+(1/10)^2 bé hơn 1
1/3 - 2/5 +3/35 - 4/63 + 5/99 - 6/143
Cíuuu
Bài 1: Tính nhanh
1) B= \(\dfrac{1}{15}+\dfrac{1}{35}+\dfrac{1}{63}+\dfrac{1}{99}+\dfrac{1}{143}\)
2) C= \(\dfrac{1}{2}+\dfrac{1}{14}+\dfrac{1}{35}+\dfrac{1}{65}+\dfrac{1}{104}+\dfrac{1}{152}\)
Bài 2: Chứng minh
\(\dfrac{1}{101}+\dfrac{1}{102}+\dfrac{1}{103}+\dfrac{1}{299}+\dfrac{1}{300}>\dfrac{2}{3}\)