Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
A)6 và 4/5-(1 và 2/3+3 và 4/5)
=6+4/5-1-2/3-3-4/5
=(6-1-3)+(4/5-4/5)-2/3
=2-2/3=1 và 1/3
B)[(19+5/8/7/12)-(13+1/4/7/12)]X4/5
=[(19-13)+(5/8/7/12-1/4/7/12)]X4/5
=[6+3/8/7/12]X4/5
=[6+9/14]X4/5
=93/14 X4/5=186/35
nhớ
A) cách 1\(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}\)
\(=\frac{9}{5}\cdot\frac{15}{17}+\frac{8}{5}\cdot\frac{15}{17}\)
\(=\frac{135}{85}+\frac{120}{85}\)
\(=\frac{255}{85}\)
\(=3\)
Cách 2\(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}\)
\(=\frac{9}{5}\cdot\frac{15}{17}+\frac{8}{5}\cdot\frac{15}{17}\)
\(=\frac{15}{17}\cdot\left(\frac{9}{5}+\frac{8}{5}\right)\)
=\(\frac{15}{17}\cdot\frac{17}{5}\)
\(=\frac{15\cdot17}{17\cdot5}\)
\(=\frac{5\cdot3\cdot17}{17\cdot5}\)
\(=3\)
B) Cách 1 :
0,9 : 0,25 + 1,05 : 0,25
= 3,6 + 4,2
=7,8
Cách 2:
0,9 : 0,25 + 1,05 : 0,25
\(=0,9:\frac{1}{4}+1,05:\frac{1}{4}\)
\(=0,9\cdot4+1,05\cdot4\)
\(=4\cdot\left(0,9+1,05\right)\)
\(=4\cdot1,95\)
=\(7,8\)
\(\frac{5}{9}\times\frac{12}{7}=\frac{5\times12}{9\times7}=\frac{5\times4\times3}{3\times3\times7}=\frac{20}{21}\)
\(\frac{6}{5}:\frac{8}{3}=\frac{6}{5}\times\frac{8}{3}=\frac{2\times3\times8}{5\times3}=\frac{16}{5}\)
\(\frac{9}{20}\times\frac{5}{12}=\frac{3\times3\times5}{4\times5\times4\times3}=\frac{3}{16}\)
\(\frac{15}{16}:\frac{25}{24}=\frac{15}{16}\times\frac{24}{25}=\frac{3\times5\times4\times2\times3}{4\times2\times2\times5\times5}=\frac{9}{10}\)
\(14\times\frac{5}{21}=\frac{2\times7\times5}{3\times7}=\frac{10}{3}\)
\(10:\frac{5}{3}=10\times\frac{3}{5}=\frac{2\times5\times3}{5}=6\)
\(\frac{5}{3}:10=\frac{5}{3}\times\frac{1}{10}=\frac{5}{3\times2\times5}=\frac{1}{6}\)
\(\frac{3}{7}\times\frac{1}{3}+\frac{3}{7}\times\frac{4}{3}-\frac{3}{7}\times\frac{1}{9}\)
\(\frac{3}{7}\times\left(\frac{1}{3}+\frac{4}{3}-\frac{1}{9}\right)\)
\(\frac{3}{7}\times\left(\frac{5}{3}-\frac{1}{9}\right)\)
\(\frac{3}{7}\times\left(\frac{45}{27}-\frac{3}{27}\right)\)
\(\frac{3}{7}\times\frac{14}{9}\)
\(\frac{2}{3}\)
\(\frac{7}{15}\times\frac{6}{5}+\frac{3}{5}\times\frac{6}{5}-\frac{17}{30}:\frac{5}{6}\)
\(\frac{7}{15}\times\frac{6}{5}+\frac{3}{5}\times\frac{6}{5}-\frac{17}{30}\times\frac{6}{5}\)
\(\left(\frac{7}{15}+\frac{3}{5}-\frac{17}{30}\right)\times\frac{6}{5}\)
\(\left(\frac{14}{30}+\frac{18}{30}-\frac{17}{30}\right)\times\frac{6}{5}\)
\(\frac{1}{2}\times\frac{6}{5}\)
\(\frac{3}{5}\)
Chúc bạn học tốt !!!
37×13+37×43−37×1937×13+37×43−37×19
37×(13+43−19)37×(13+43−19)
37×(53−19)37×(53−19)
37×(4527−327)37×(4527−327)
37×14937×149
23
\(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}=\frac{9}{5}.\frac{15}{17}+\frac{8}{5}.\frac{15}{17}=\frac{15}{17}.\left(\frac{9}{5}+\frac{8}{5}\right)=\frac{15}{17}.\frac{17}{5}=\frac{15}{5}=3\)
0,9:0,25+1,05:0,25 = 0,9.4+1,05.4 = 4.(0,9+1,05)=4 . 1,95=7,8
\(\frac{5}{3.9}+\frac{5}{9.15}+.........+\frac{5}{63.69}\)
\(=\frac{5}{6}.\left(\frac{6}{3.9}+\frac{6}{9.15}+..........+\frac{6}{63.69}\right)\)
\(=\frac{5}{6}.\left(\frac{1}{3}-\frac{1}{9}+\frac{1}{9}-\frac{1}{15}+......+\frac{1}{63}-\frac{1}{69}\right)\)
\(=\frac{5}{6}.\left(\frac{1}{3}-\frac{1}{69}\right)=\frac{5}{6}.\frac{22}{69}=\frac{55}{207}\)