Ta có: \(3\frac{1}{3}+7\frac{3}{17}\cdot\frac{2}{15}-2\frac{3}{17}\cdot\frac{2}{15}\)
\(=\frac{10}{3}+\frac{122}{17}\cdot\frac{2}{15}-\frac{37}{17}\cdot\frac{2}{15}\)
\(=\frac{10}{3}+\frac{244}{255}-\frac{74}{255}\)
\(=\frac{10}{3}+\frac{2}{3}=\frac{12}{3}=4\)
1, Tính
a, 2008 . 2008 - 2010 . 2006
b, \(\dfrac{232323.29}{23.292929}\)
c, \(\dfrac{\left(2^{17}+5^{17}\right).\left(3^{14}-5^{12}\right).\left(2^4-4^2\right)}{15^2+5^3+67^7}\)
2, So sánh \(\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{100}}\) với 1
thực hiện phép tính
a\(\dfrac{5}{7}+\dfrac{9}{23}+\dfrac{-12}{7}+\dfrac{14}{23}\)
b\(\left(7-2\dfrac{3}{5}\right).2\dfrac{4}{33}-2\dfrac{3}{5}:\dfrac{1}{2}+\dfrac{7}{5}\)
c\(\dfrac{-7}{9}:\dfrac{8}{15}+\dfrac{-7}{9}.\dfrac{7}{15}+5\dfrac{7}{9}\)
d\(\left(16\dfrac{3}{8}-19\dfrac{3}{4}\right)-\left(12\dfrac{3}{8}-17\dfrac{3}{4}\right)\)
giúp mình nhé
\(5\dfrac{8}{17}:x+\left(\dfrac{-4}{17}\right):x+3\dfrac{1}{7}:17\dfrac{1}{3}=\dfrac{4}{11}\)
Bài 2: Tính hợp lý:
\(A=\dfrac{63636337-37373763}{1+2+3+...+2006}\)
\(B=1\dfrac{6}{41}\left(\dfrac{12+\dfrac{12}{19}-\dfrac{12}{37}-\dfrac{12}{53}}{3+\dfrac{1}{3}-\dfrac{3}{37}-\dfrac{3}{53}}:\dfrac{4+\dfrac{4}{17}+\dfrac{4}{19}+\dfrac{4}{2006}}{5+\dfrac{5}{17}+\dfrac{5}{19}+\dfrac{5}{2006}}\right)\dfrac{124242423}{237373735}\)
tính M = \(\dfrac{1,6:\left(1\dfrac{3}{5}.1,25\right)}{0,64-\dfrac{1}{25}}+\dfrac{\left(1,08-\dfrac{2}{25}\right):\dfrac{4}{7}}{\left(5\dfrac{5}{9}-2\dfrac{1}{4}\right).2\dfrac{2}{17}}+0,6.0,5:\dfrac{2}{5}\)
Câu 1. Cho A=\(\dfrac{1}{2^2}\)+\(\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{2012^2}\). So sánh A và 1.
Câu 2. Tính \(A=2014+\dfrac{2014}{1+2}+\dfrac{2014}{1+2+3}+\dfrac{2014}{1+2+3+4}+...+\dfrac{2014}{1+2+3+4+...+2013}\)
Câu 3. Cho A=\(\dfrac{6n+42}{6n}\)với n \(\in\) Z và n \(\ne\) 0. Tìm tất cả các số nguyên n sao cho A cũng là số nguyên.
Câu 4. So sánh A=\(\dfrac{17^{18}+1}{17^{19}+1}\) và B=\(\dfrac{17^{17}+1}{17^{18}+1}\).
1. Chứng minh:
\(\dfrac{1}{3}-\dfrac{2}{3^2}+\dfrac{3}{3^3}-\dfrac{4}{3^4}+...+\dfrac{99}{3^{99}}-\dfrac{100}{3^{100}}< \dfrac{3}{16}\)
2. Cho:
\(M=\dfrac{1}{15}+\dfrac{1}{105}+\dfrac{1}{315}+...+\dfrac{1}{1977}\). So sánh M với 12.
tìm x
\(\dfrac{5}{3}x-2\dfrac{1}{3}=-\dfrac{4}{3}.1\dfrac{1}{8}-\dfrac{2}{3}\)
\(2\dfrac{1}{6}:x-\dfrac{-5}{8}=\dfrac{-7}{15}:4\dfrac{1}{5}-\dfrac{-6}{7}\)
\(\left(\dfrac{5}{6}x-0,3\right):2\dfrac{1}{3}=25\%\)
\(\dfrac{4}{7}-\dfrac{2}{3}x=1,5+\dfrac{4}{5}x\)
GIÚP MÌNH NHÉ
1) Tmf tập hợp A sao cho các số nguyên a sao cho: \(\dfrac{1}{2}+\dfrac{1}{34}\)≤\(\dfrac{a}{17}\)bé hơn \(\dfrac{15}{17}-\dfrac{3}{17}\)
2) Cho biểu thức A=\(\dfrac{2}{n-1}\)(n ∈ Z)
Tìm tất cả các giá trị nguyên của n để A là số nguyên
