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\(A=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-1\frac{15}{17}+\frac{2}{3}=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-\frac{64}{34}+\frac{14}{21}=\left(\frac{15}{34}+\frac{9}{34}-\frac{64}{34}\right)+\left(\frac{7}{21}+\frac{14}{21}\right)=\frac{30}{34}+\frac{21}{21}=\frac{15}{17}+1=\frac{32}{17}\)
a, \(-\frac{187}{70}\)
b,\(\frac{27}{70}\)
c,\(\frac{53}{14}\)
d,\(\frac{27}{4}\)
e,1
f,\(\frac{23}{4}\)
g,-1
i,6
k,315
l,\(\frac{9}{2}\)
1. a) 3+2=5
b) 0,5-0,1=0,4
c) 4/5-1/9=31/45
d) 2-0,6=1,4
2. a) 8-4+3=7
b) 11+5-3=13
c) 3/2-4/6-7-37/6
d) 4+5-6=3
a) \(\frac{17}{9}-\frac{17}{9}:\left(\frac{7}{3}+\frac{1}{2}\right)\)
= \(\frac{17}{9}-\frac{17}{9}:\frac{17}{6}\)
= \(\frac{17}{9}-\frac{2}{3}\)
= \(\frac{11}{9}\)
b) \(\frac{4}{3}.\frac{2}{5}-\frac{3}{4}.\frac{2}{5}\)
= \(\frac{2}{5}.\left(\frac{4}{3}-\frac{3}{4}\right)\)
= \(\frac{2}{5}.\frac{7}{12}\)
= \(\frac{7}{30}\)
Mình lười làm quá, hay mình nói kết quả cho bn thôi nha
c) -6
d) 3
e) 3
g) 12
h) \(\frac{23}{18}\)
i) \(\frac{-69}{20}\)
k) \(\frac{-1}{2}\)
l) \(\frac{49}{5}\)
\(b,\left(\sqrt{1\frac{9}{16}-\sqrt{\frac{9}{16}}}\right):5\)
\(=\left(\sqrt{\frac{25}{16}-\frac{3}{4}}\right):5\)
\(=\sqrt{\frac{13}{16}}:5\)
\(=\frac{\sqrt{13}}{4}:5\)
\(=\frac{\sqrt{13}}{20}\)
a) \(5\frac{3}{7}+\frac{7}{29}-0,7-\frac{3}{17}+\frac{22}{19}-2,3\)
\(=\frac{38}{7}+\frac{7}{29}-\frac{7}{10}-\frac{3}{17}+\frac{22}{19}-\frac{23}{10}\)
\(=\left(-\frac{7}{10}-\frac{23}{10}\right)+\frac{38}{7}+\frac{7}{29}-\frac{3}{17}+\frac{22}{19}\)
\(=\left(-3\right)+\frac{38}{7}+\frac{7}{29}-\frac{3}{17}+\frac{22}{19}\)
\(=\frac{17}{7}+\frac{7}{29}-\frac{3}{17}+\frac{22}{19}\)
\(=\frac{8605}{3451}+\frac{22}{19}\)
\(\approx4.\)
d) \(\sqrt{0,36}-\sqrt{0,81}+\sqrt{0,49}\)
\(=0,6-0,9+0,7\)
\(=\left(-0,3\right)+0,7\)
\(=0,4.\)
Chúc bạn học tốt!
a) -90/189 + 45/84 - 78/126
= -10/21 + 15/28 - 13/21
= (-10/21 - 13/21) + 15/28
= -24/21 + 15/28
= -17/28
Bài 2 : Bài giải
\(a,\text{ }\sqrt{\frac{81}{100}}-\sqrt{0,49}+9,3=\sqrt{\frac{9^2}{10^2}}-\sqrt{\frac{49}{100}}+9,3=\frac{9}{10}-\sqrt{\frac{7^2}{10^2}}+9,3\)
\(=\frac{9}{10}-\frac{7}{10}+9,3=\frac{1}{5}+9,3=0,2+9,3=9,5\)
\(b,\text{ }\frac{7}{17}+\frac{10}{17}\cdot\left(\frac{-3}{5}+\frac{1}{2}\right)^2=\frac{7}{17}+\frac{10}{17}\cdot\left(-\frac{1}{10}\right)^2=\frac{7}{17}+\frac{10}{17}\cdot\frac{1}{100}=\frac{70}{170}+\frac{1}{170}=\frac{71}{170}\)
\(c,\text{ }\sqrt{121}-0,25+\sqrt{\frac{25}{36}}=11-\frac{1}{4}+\frac{5}{6}=\frac{132}{12}-\frac{3}{12}+\frac{10}{12}=\frac{139}{12}\)
Bài 2 :
a ) \(\sqrt{\frac{81}{100}}-\sqrt{0,49}+9,3=\sqrt{\frac{9^2}{10^2}}-\sqrt{\frac{49}{100}}+9,3\)
\(=\frac{9}{10}-\sqrt{\frac{7^2}{10^2}}+9,3=\frac{9}{10}-\frac{7}{10}+9,3\)
\(=\frac{1}{5}+9,3=0,2+9,3=9,5\)
b ) \(\frac{7}{17}+\frac{10}{17}\cdot\left(\frac{-3}{5}+\frac{1}{2}\right)^2=\frac{7}{17}+\frac{10}{17}\cdot\left(-\frac{1}{10}\right)^2=\frac{7}{17}+\frac{10}{17}\cdot\frac{1}{100}\)
\(=\frac{70}{170}+\frac{1}{170}=\frac{71}{170}\)
c ) \(\sqrt{121}-0,25+\sqrt{\frac{25}{36}}=11-\frac{1}{4}+\frac{5}{6}\)
\(=\frac{132}{12}-\frac{3}{12}+\frac{10}{12}=\frac{139}{12}\)