A=2/2.5+2/5.8+2/8.11+...+2/95.98
=2/3.(3/2.5+3/5.8+3/8.11+...+3/95.98)
=2/3.(1/2-1/5+1/5-1/8+1/8-1/11+...+1/95-1/98)
=2/3.(1/2-1/98)
=2/3.24/49
=16/49
VẬY A=16/49
Bài 5: (0,5 điểm) Tính giá trị biểu thức \(A=\dfrac{1}{2.5}+\dfrac{1}{5.8}+\dfrac{1}{8.11}+...+\dfrac{1}{92.95}+\dfrac{1}{95.98}\)
A=2/1.3+2/3.5+2/3.7+....+2/2021.2023
=)
B=1/2.5+1/5.8+1/8.11+...+1/95.98
A=2/2.5 + 2/5.8 +2/8.11+...2/92.95+ 2/95.98. giúp bé vs ạ.bé sẽ tick đúng cho mn nhé
A= 1/2.5+1/5.8+1/8.11+...+1/92.95+1/95.98.
Tính tổng A
A= 1/2.5+1/5.8+1/8.11+...+1/92.95+1/95.98.
Tính tổng A?
A=1/2.5+1/5.8+1/8.11+...+1/92.95+1/95.98
A=1/2.5+1/5.8+1/8.11+......+1/92.95+1/95.98
\(A=\dfrac{1}{2.5}+\dfrac{1}{5.8}+\dfrac{1}{8.11}+...+\dfrac{1}{92.95}+\dfrac{1}{95.98}\)
A=1/2.5+1/5.8+1/8.11+.....+1/92.95+1/95.98
A=?
