M= 4/2.5 + 4/5.8 + 4/8.11 + 4/11.14 + 4/14.17 + 4/17.20
Tính S
S=1/2.5+1/5.8+1/8.11+1/11.14+1/14.17+1/17.20
Tính tổng :
M= 4/2.5 + 4/5.8 + 4/8.11 + 4/11.14 + 4/14.17 + 4/17.20
\(\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+\frac{1}{14.17}+\frac{1}{17.20}\)
so sánh A với 1 , biếtA = \(\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+\frac{1}{14.17}+\frac{1}{17.20}\)
Tìm x:
3.x/2.5+3.x/5.8+3.x/8.11+3.x/11.14+3.x/14.17= hỗn số âm 1 ba phần 5
\(\dfrac{3}{2.5}\)+\(\dfrac{3}{5.8}\)+\(\dfrac{3}{8.11}\)\(\dfrac{3}{11.14}\)+\(\dfrac{3}{14.17}\)<\(\dfrac{1}{2}\)
Ai giúp mình huhu
Bài 4 tìm số nguyên X
1.a 4/5 -5/6<x/30<1/3-3/10
b -x/2 + 2x/3 + x+1/4+2x+1/6 = 8/3
2.
1/3.4+1/4.5+...+1/x(x+1)=3/10
Bài5 chứng tỏ
A 3/2.5+3/5.8+3/8.11+3/11.14+3/14.17<1/2
B 1/2 + 1/32+1/42+...+1/102<1
Nhanh +Đúng = Tick ( gắp )
\(A=\frac{1}{2.5}\frac{1}{5.8}\frac{1}{8.11}\frac{1}{11.14}\frac{1}{14.17}\frac{1}{17.20}\)
\(B=8400.\left(\frac{1}{1.5}+\frac{1}{5.9}+\frac{1}{9.13}+\frac{1}{13.17}+\frac{1}{17.21}+\frac{1}{21.25}\right)\)