Tính :
a) A = 1.2.3 . ..... . 100 - 1.2.3. ... .99 - 1.2.3.98.992
b) B = \(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right).\frac{21}{24}\)
Bạn nào làm đúng , nhanh mk tick cho
Tính nhanh :
\(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right).\frac{21}{24}\)
\(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right).\frac{21}{24}\)
\(=\left(\frac{136}{15}-\frac{28}{5}+\frac{31}{5}\right).\frac{21}{24}\)
\(=\left[\frac{136}{15}-\left(\frac{28}{5}-\frac{31}{5}\right)\right].\frac{21}{24}\)
\(=\left(\frac{136}{15}+\frac{3}{5}\right).\frac{21}{24}\)
\(=\frac{29}{3}.\frac{21}{24}\)
\(=\frac{203}{24}\)
Study well ! >_<
a,\(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right)\frac{21}{24}\)
Thực hiện phép tính để tính giá trị các biểu thức sau:
\(a,A=\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right).\frac{21}{24}\)
\(b,B=70.\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)
\(c,C=\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
a) A= ( 136/15 - 28/5 + 62/10) .21/24
A= (136/15 - 84/15 + 93/15) . 7/8
A= 145/15. 7/8
A= 203/24
b) B= 70 .( 131313.565656 + 131313/727272 + 131313/ 909090)
= 70. ( 13/56+ 13/72 + 13/90)
= 70 . 39/70
= 39
Tính :
\(A=\frac{28}{15}.\left(\frac{1}{2}\right)^2.3+\left(\frac{8}{15}-\frac{79}{60}\right).\frac{24}{47}\)
\(B=\frac{75}{100}.\frac{28}{15}-\left(\frac{104}{195}+\frac{25}{100}\right).\frac{24}{47}-\frac{51}{13}.\frac{1}{3}\)
Ai làm xong mk k nha!!!
mik ko ghi lại đề nhé!
\(A=\left(\frac{18}{15}.\frac{1}{4}.3\right)+\left(-\frac{47}{60}\right).\frac{24}{47}\)
\(A=\frac{8}{5}+\left(-\frac{2}{5}\right)\)
\(A=\frac{6}{5}\)
\(B=\frac{3}{4}.\frac{28}{15}-\left(\frac{8}{15}+\frac{1}{4}\right).\frac{24}{47}-\frac{17}{13}\)
\(B=\frac{7}{5}-\frac{47}{60}.\frac{24}{47}-\frac{17}{13}\)
\(B=\frac{7}{5}-\frac{2}{5}-\frac{17}{13}\)
\(B=1-\frac{17}{13}\)
\(B=-\frac{4}{13}\)
THANKS
Tính
a)\(A=\frac{8}{9}.\frac{15}{16}.\frac{24}{25}....\frac{2499}{2500}\)
b)\(B=\left(1-\frac{1}{3}\right)\left(1-\frac{1}{6}\right)\left(1-\frac{1}{10}\right)\left(1-\frac{1}{15}\right)...\left(1-\frac{1}{780}\right)\)
GIÚP mk vs ạ , ai nhanh đúng mk sẽ tick ạ
OK chờ tí nhé
câu a tách ra nha
câu b thì tính trong ngoặc rồi tách
hok tốt
...
Câu a tham khảo link này nha bn
https://olm.vn/hoi-dap/detail/186073292336.html
(\(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\)) .\(\frac{21}{24}\)
\(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right)\cdot\frac{21}{24}\)
=
\(=\left(\frac{272}{30}+-\frac{168}{30}+\frac{186}{30}\right).\frac{7}{8}\)\(=\frac{29}{3}.\frac{7}{8}=\frac{203}{24}\)
a) \(\left(\frac{9}{10}-\frac{15}{16}\right).\left(\frac{5}{12}-\frac{11}{15}-\frac{7}{20}\right)\)
B) \(\frac{-3}{5}+\frac{28}{5}.\left(\frac{43}{56}+\frac{5}{24}-\frac{21}{63}\right)\)
thực hiện phép tính
Tính giá trị của biểu thức
A=1.2.3........100-1.2.3.....99-1.2.3.....99^2
B=\(\frac{\left\{3.4.2^{16}\right\}}{11.2^{13}.4^{11}-4^9.2^{18}}\)
C=1.2+2.3+3.4+...+98.99
D=\(\frac{2}{1.3}\)+\(\frac{2}{3.5}\)+\(\frac{2}{5.7}\)+....+\(\frac{2}{99.101}\)
c) \(C=1.2+2.3+3.4+...+98.99\)
\(\Rightarrow3C=1.2\left(3-0\right)+2.3\left(4-1\right)+3.4\left(5-2\right)+...+98.99\left(100-97\right)\)
\(=1.2.3+2.3.4-1.2.3+3.4.5-2.3.4+....+98.99.100-97.98.99\)
\(=98.99.100\)
\(\Rightarrow C=\frac{98.99.100}{3}=323400\)
d) \(D=\frac{2}{1.3}+\frac{2}{3.5}+...+\frac{2}{99.101}\)
\(=1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{99}-\frac{1}{101}\)
\(=1-\frac{1}{101}=\frac{100}{101}\)
Tính giá trị biểu thức
A=\(\frac{1}{1.2.3}+\frac{1}{2.3.4}+\frac{1}{3.4.5}+....+\frac{1}{48.49.50}\)
B=\(-\frac{3}{5}.\frac{3}{8}+2\frac{3}{5}+\frac{-3}{5}.\frac{5}{8}\)
C=\(1\frac{3}{5}.0,75-\left(\frac{11}{20}-25\%\right):\frac{3}{7}\)
Ai làm nhanh và đúng câu B và C mk sẽ chọn nhé.
\(B=-\frac{3}{5}\left(\frac{3}{8}-2+\frac{5}{8}\right)\)
\(B=-\frac{3}{5}.\left(-1\right)=\frac{3}{5}\)
\(C=\frac{8}{5}.\frac{3}{4}-\left(\frac{11}{20}-\frac{1}{4}\right).\frac{7}{3}\)
\(C=\frac{6}{5}-\frac{3}{10}.\frac{7}{3}\)
\(C=\frac{6}{5}-\frac{7}{10}=\frac{1}{2}\)