\(\frac{\left(1+2+...+100\right)\cdot\left(\frac{1}{3}-\frac{1}{5}-\frac{1}{7}-\frac{1}{9}\right)\cdot\left(6,3\cdot12-21\cdot3,6\right)}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}\)
Tính giá trị biểu thức(giút gọn biểu thức)
A=\(\left(\left(\frac{2}{193}-\frac{3}{386}\right)\cdot\frac{193}{17}+\frac{33}{34}\right):\left(\left(\frac{7}{2001}+\frac{11}{4002}\right)\cdot\frac{2001}{25}+\frac{9}{2}\right)\)
\(B=\left(1+2+3+4+.....+100\right)\cdot\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{7}-\frac{1}{9}\right)\cdot\left(\frac{6}{3}\cdot12-2,1\cdot3,6\right)\)
C=\(\frac{2\cdot8^4\cdot27^2+4\cdot69}{2^7\cdot6^7+2^7\cdot40\cdot9^4}\)
\(F=1-\frac{1}{1+\frac{2}{1-\frac{3}{1-4}}}\)
ai làm đúng nhanh dễ hiểu thì mk tick cho
tính nhanh
a, \(\frac{-2}{5}\cdot\left(\frac{5}{17}-\frac{9}{15}\right)-\frac{2}{5}\cdot\frac{2}{17}+\frac{-2}{5}\)
b, \(\frac{1}{5}\cdot\left(\frac{4}{13}-\frac{9}{11}\right)+\frac{1}{3}\left(\frac{9}{13}-\frac{4}{22}\right)\)
c, \(\left(\frac{1}{2}+1\right)\cdot\left(\frac{1}{3}+1\right)\cdot\left(\frac{1}{4}+1\right)\cdot...\cdot\left(\frac{1}{99}+1\right)\)
d, \(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot...\cdot\left(1-\frac{1}{100}\right)\)
Mk ko biết lm nhưng cứ k thoải mái nha
SORRY
Tính \(A=\frac{\left(1+2+3+...+100\right)\cdot\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{4}-\frac{1}{5}\right)\cdot\left(2,4\cdot42-21\cdot4,8\right)}{1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{100}}\)
A=[(1+2+...+100) x (1/2 - 1/3 - 1/4 - 1/5) x (2,4x42 - 21x4,8)] / 1+1/2+1/3+...+1/100
= [(1+2+3+...+100) x (1/2 - 1/3 - 1/4-1/5) x (2,4x2x21 - 21x2x 4,8)] / 1+1/2+1/3+...+1/100
=[(1+2+3+...+100) x (1/2 - 1/3 - 1/4 - 1/5) x 0] / 1+1/2+1/3+...+1/100
=0 / 1+1/2+1/3+...+1/100 = 0
TÍNH
\(\frac{\left(1+2+3+...+100\right)\times\left(\frac{1}{3}-\frac{1}{5}-\frac{1}{7}-\frac{1}{9}\right)\times\left(6,3\times12-21\times3,6\right)}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}\)
Dễ thấy 6,3 . 12 - 21 . 3,6 = 63 . 1,2 - 63 . 1,2 = 0
Do đó biểu thức trên bằng 0
a) \(\left(\frac{11}{4}\cdot\frac{-5}{9}-\frac{4}{9}\cdot\frac{11}{4}\right)\cdot\frac{8}{33}\)
b) \(\frac{-1}{4}\cdot\frac{152}{11}+\frac{68}{4}\cdot\frac{-1}{11}\)
c) \(\frac{-2}{3}\cdot\frac{4}{5}+\frac{2}{3}\cdot\frac{3}{5}\)
d) \(\left(\frac{1}{2}-1\right)\cdot\left(\frac{1}{3}-1\right)\cdot\left(\frac{1}{4}-1\right)\cdot....\cdot\left(\frac{1}{100}-1\right)\)
e) \(\frac{3}{2^2}\cdot\frac{8}{3^2}\cdot\frac{15}{4^2}\cdot...\cdot\frac{8^{99}}{30^2}\)
a) \(\left(\frac{11}{4}.\frac{-5}{9}-\frac{4}{9}.\frac{11}{4}\right).\frac{8}{33}\)
=\(\frac{11}{4}\left(-\frac{5}{9}-\frac{4}{9}\right).\frac{8}{33}\)
=\(\frac{11}{4}\cdot-1\cdot\frac{8}{33}\)
=\(-\frac{11}{4}\cdot\frac{8}{33}\)
=\(-\frac{2}{3}\)
b)\(-\frac{1}{4}\cdot\frac{152}{11}+\frac{68}{4}\cdot-\frac{1}{11}\)
=\(\frac{-1.152}{4.11}+\frac{68}{4}\cdot\frac{-1}{11}\)
=\(\frac{-1.152}{11.4}+\frac{68}{4}\cdot\frac{-1}{11}\)
=\(\frac{-1}{11}\cdot\frac{152}{4}+\frac{68}{4}\cdot\frac{-1}{11}\)
=\(\frac{-1}{11}\cdot\left(\frac{152}{4}+\frac{68}{4}\right)\)
=\(\frac{-1}{11}\cdot55=-5\)
c)\(\frac{-2}{3}\cdot\frac{4}{5}+\frac{2}{3}\cdot\frac{3}{5}\)
=\(-1\cdot\frac{2}{3}\left(\frac{4}{5}+\frac{3}{5}\right)\)
=\(-1\cdot\frac{2}{3}\cdot\frac{7}{5}\)
=\(-\frac{2}{3}\cdot\frac{7}{5}\)
=\(\frac{-14}{15}\)
d) chưa nghĩ ra nhé
e) bạn chép sai đề bài rồi
mk mới kiểm tra 45 phút nên biết
đề bài nè
\(\frac{3}{2^2}\cdot\frac{8}{3^2}\cdot\frac{15}{4^2}\cdot...\cdot\frac{899}{30^2}\)
=\(\frac{1.3}{2^2}\cdot\frac{2.4}{3^2}\cdot\frac{3.5}{4^2}\cdot...\cdot\frac{29.31}{30^2}\)
=\(\frac{1.3.2.4.3.5...29.31}{2.2.3^2.4^2...30.30}\)
=\(\frac{1.2.3^2.4^2.5^2....29^2.30.31}{2.2.3^2.4^2.5^2....29^2.30.30}\)
=\(\frac{1.31}{2.30}\)
=\(\frac{31}{60}\)
a)trong ngoac bn dat thau so chung la 11/4 rui tinh binh thuong b)bn tu lam nhe c)dat thua so chung d)tinh trong ngoac ra rui nhan vs e) mk bo tay
Tính
a)\(5^2-\left(-5\right)^3+\frac{1}{2}-\left(\frac{1}{2}\right)^2\)
b)\(2\frac{3}{4}-\frac{1}{8}\cdot1\frac{1}{2}\)
c)\(\left(\frac{1}{3^5}+\frac{1}{3^6}+\frac{1}{3^7}+\frac{1}{3^8}\right)\cdot3^9\)
d)\(\left(\frac{1}{2^2}-1\right)\cdot\left(\frac{1}{3^2}-1\right)\cdot\cdot\cdot\cdot\left(\frac{1}{100^2}-1\right)\)
tình hợp lí:
\(\frac{\left(\frac{1}{5}-\frac{2}{7}\right)\cdot\frac{3}{4}-\frac{3}{4}\cdot\left(\frac{1}{3}-\frac{2}{7}\right)}{\frac{1}{5}\cdot\frac{2}{7}-\frac{1}{3}\cdot\left(\frac{2}{7}+\frac{3}{9}\right)+\frac{3}{9}+\frac{1}{5}}\)
tinh hop li :
\(\frac{\left(\frac{1}{5}-\frac{2}{7}\right)\cdot\frac{3}{4}-\frac{3}{4}\cdot\left(\frac{1}{3}-\frac{2}{7}\right)}{\frac{1}{5}\cdot\frac{2}{7}-\frac{1}{3}\cdot\left(\frac{2}{7}+\frac{3}{9}\right)+\frac{3}{9}+\frac{1}{5}}\)
Tính giá trị biểu thức :
\(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot....\cdot\left(1-\frac{1}{99}\right)\cdot\left(1-\frac{1}{100}\right)\)
Ta có:
\(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{99}\right).\left(1-\frac{1}{100}\right)\)
\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{98}{99}.\frac{99}{100}\) \(=\frac{1.2.3...98.99}{2.3.4...99.100}=\frac{1}{100}\)
nha