tính
2,\(A=\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}+\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}\)
3,\(B=\frac{\frac{1}{3}-\frac{1}{7}-\frac{1}{13}}{\frac{2}{3}-\frac{2}{7}-\frac{2}{13}}.\frac{\frac{1}{3}-0,25+0,2}{1\frac{1}{6}-0,875+0,7}+\frac{6}{7}\)
tính b
b=\(\frac{0,275-0,5+\frac{3}{11}}{0,625+0,5+\frac{5}{11}}:\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}\)
So sánh
A=\(\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^9}+.....+\frac{1}{3^{33}}với\frac{1}{2}\)
Tính:1)A=\(\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}+\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}\)
B=\(\frac{\frac{1}{3}-\frac{1}{7}-\frac{1}{13}}{\frac{2}{3}-\frac{2}{7}-\frac{2}{13}}\times\frac{\frac{1}{3}-0,25+0,2}{1\frac{1}{6}-0,875+0,7}+\frac{6}{7}\)
\(\dfrac{0,375-0,3+\dfrac{3}{11}+\dfrac{3}{12}}{-265+0,5-\dfrac{5}{11}-\dfrac{5}{12}}\)+\(\dfrac{1,5+1-0,75}{2,5+\dfrac{5}{3}-1,25}\)
\(\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}+\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}\)
Cho 1^2+2^2+3^2+...+3^2=385
Tính S=(0,25)^2+(0,5)^2+(0,75)^2+...+(2,5)^2
\(A=\left(\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}+\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}\right):\frac{1890}{2005}+115\)
\(\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,265+0,5-\frac{5}{11}-\frac{5}{12}}+\frac{1,5+1-0,75}{2,5+\frac{5}{3}-\frac{5}{4}}\)
Bài 2: Các số sau có phải là số chính phương không?
1. 13 + 23 ; 13 + 23 + 33 ; 13 + 23 + 33 + 43 ; 13 + 23 + 33 + 43 + 53
2. 1262 + 1 ; 100! + 8 ; 1012 - 3 ; 1010 + 7 ; 11 + 112 + 113
3. 32 + 22 b) 62 + 82 c) 400 - 162 d) 2.3.45.7.9.11.13 + 2018 e) 13 + 23
4. m) 1262 + 1 n) 100!+ 8 p) 1012 - 3 q) 1010 + 7 k) 11 + 112 + 113
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