\(b,\left(x+\frac{1}{2}\right)+\left(x+\frac{1}{4}\right)+\left(x+\frac{1}{8}\right)+...+\left(x+\frac{1}{1024}\right)=1\)
\(a,\left(x+\frac{1}{2}\right)+\left(x+\frac{1}{4}\right)+\left(x+\frac{1}{8}\right)+\left(x+\frac{1}{16}\right)=1\)
\(c,\frac{1}{4}+\frac{1}{28}+\frac{1}{70}+\frac{1}{130}+...+\frac{1}{x.x+3}=\frac{34}{103}\)
\(d,\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{1}{x.\left(x+1\right):2}=\frac{2009}{2011}\)
HỘ MÌNH VỚI . GẤP . MAI MÌNH ĐI HỌC RỒI . THANKS TRƯỚC NÀ . MÌNH SẼ TICK CHO BẠN NÀO TRẢ LỜI ĐÚNG NHẤT VÀ NHANH NHẤT NHÉ
1.Tìm x,biết:
a) \(\frac{-3}{2}.\left(7-\frac{1}{6}\right)+4.\left(x-\frac{1}{2}\right)=3\)
b) \(3.\left(x-\frac{1}{5}\right)-7.\left(\frac{5}{14}-3\right)=20\)
c) \(-\frac{3}{5}.\left(x-10\right)=\frac{4}{7}.\left(14-\frac{1}{8}\right)\)
Bạn nào giúp mình ( có cách làm) Cho 3 tick liên tiếp luôn nè
so sánh với 3
các bạn giúp mik với
\(\left(1+\frac{1}{2}\right)+\left(1+\frac{1}{5}\right)+\left(1+\frac{1}{9}\right)+...+\left(1+\frac{2}{n^2+3n}\right)\)
+Tim x :
a ) \(\left(x-\frac{1}{2}\right)^3=\frac{1}{27}\)
b )\(\left(x+\frac{1}{2}\right)^2=\frac{4}{25}\)
c ) \(\left(x+1\right)^{x+2}=\left(x-1\right)^{x+6}\) (x ϵ Z )
d ) \(\left(2x+3\right)^{2016}=\left(2x+3\right)^{2018}\)
e ) \(\frac{3}{x+2.x+5}+\frac{5}{x+5.x+10}+\frac{7}{x+10.x+17}=\frac{x}{x+2.x+17}\) Với \(x\notin\left\{-2;-5;-10;-17\right\}\)
tìm số x , biết :
a) \(\frac{2}{3}x-\frac{3}{2}x=\frac{5}{12}\)
b) \(\frac{2}{5}+\frac{3}{5}.\left(3x-3,7\right)=\frac{-53}{10}\)
c) \(\frac{7}{9}:\left(2+\frac{3}{4}x\right)+\frac{5}{9}=\frac{23}{27}\)
d) \(\frac{-2}{3}.x+\frac{1}{5}=\frac{3}{10}\)
e) \(\left|x\right|-\frac{3}{4}=\frac{5}{3}\)
f) \(\left|2x-\frac{1}{3}\right|+\frac{5}{6}=1\)
Bài 1: a) \(A=\frac{5}{11.16}+\frac{5}{16.21}+\frac{5}{21.26}+...+\frac{5}{61.66}\)
b) \(B=\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\)
c) \(C=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{1989.1990}\)
Bài 2: a. Tính tổng: \(M=\frac{10}{56}+\frac{10}{140}+\frac{10}{260}+...+\frac{10}{1400}\)
b. Cho: \(S=\frac{3}{10}+\frac{3}{11}+\frac{3}{12}+\frac{3}{13}+\frac{3}{14}\) chứng minh rằng 1 < S < 2
Bài 3: Tính giá trị của biểu thức sau:
\(A=\left(\frac{1}{7}+\frac{1}{23}-\frac{1}{1009}\right):\left(\frac{1}{23}+\frac{1}{7}-\frac{2}{2009}+\frac{1}{7}.\frac{1}{23}.\frac{1}{2009}\right)+1:\left(30.1009-160\right)\)
Bài 4: Tính nhanh:
\(\text{a) 35 . 34 + 35 . 86 + 67 . 75 + 65 . 45}\)
\(\text{b) 21 . }7^2-11.7^2+90.7^2+49.125.16\)
Bài 5: Thực hiện phép tinh sau:
a. \(\frac{2181.729+243.81.27}{3^2.9^2.234+18.54+162.9+723.729}\)
b. \(\frac{1}{1.2+}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{98.99}+\frac{1}{99.100}\)
c. \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{100^2}< 1\)
d. \(\frac{5.4^{15}-9^9-4.3^{20}}{5.2^{19}.6^{19}-7.2^{29}.27^6}\)
giúp mk nha! nhớ viết cách làm nha!
Tìm x biết:
a) \(\frac{-3}{2}.\left(7-\frac{1}{6}\right)+4.\left(x-\frac{1}{2}\right)=3\)
b)\(3.\left(x-\frac{1}{5}\right)-7.\left(\frac{5}{14}-3\right)=20\)
Bạn nào làm ơn giúp mình có cách làm cho 4 tick
tìm x biết :
a) \(\left(x+\frac{1}{2}\right).\left(\frac{2}{3}-2x\right)=0\)
b) \(\left(x.6\frac{2}{7}+\frac{3}{7}\right).2\frac{1}{5}-\frac{3}{7}=-2\)
c) \(x.3\frac{1}{4}+\left(-\frac{7}{6}\right).x-1\frac{2}{3}=\frac{5}{12}\)
d) \(5\frac{8}{17}:x+\left(-\frac{4}{17}\right):x+3\frac{1}{7}:17\frac{1}{3}=\frac{4}{11}\)
e) \(\frac{17}{2}-\left|2x-\frac{3}{4}\right|=-\frac{7}{4}\)
tính hợp lí ( nếu có thể )
\(\frac{1}{3}.\frac{-6}{13}.\frac{-9}{10}.\frac{-13}{36}\)
\(\frac{-1}{3}.\frac{-15}{17}.\frac{34}{45}\)
\(\left(1-\frac{1}{5}\right).\left(\frac{-3}{10}+\frac{1}{5}\right)\)
\(A=\frac{1}{3}\times\frac{4}{5}+\frac{1}{3}\times\frac{6}{5}+\frac{2}{3}\)
\(11\frac{1}{4}-\left(2\frac{5}{7}+5\frac{1}{4}\right)\)