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\(A=\left[0,8.7\left(0,8\right)^2\right].\left(1,25.7-\frac{4}{5}.1,25\right)+31,64\)
\(=0,8.\left(7+0,8\right).1,25.\left(7-0,8\right)+31,64\)
\(=0,8.7,8.1,25.6,2+31,64\)
\(=6,24.7,75+31,64\)
\(=48,36+31,64=80\)
\(B=\frac{\left(1,09-0,29\right).\frac{5}{4}}{\left(18,9-16,65\right).\frac{8}{9}}=\frac{0,8.1,25}{2,25.\frac{8}{9}}=\frac{1}{2}\)
\(A:B=80:\frac{1}{2}=160\)
Vậy A gấp 160 lần B.
\(\frac{1}{20}\left(x-\frac{8}{15}\right)=-\frac{1}{30}\) \(\left(28+\frac{1}{5}\right).\left(\frac{3}{5}.x+\frac{4}{7}\right)=0\)
\(x-\frac{8}{15}=-\frac{1}{30}:\frac{1}{20}\) \(\frac{141}{5}.\left(\frac{3}{5}.x+\frac{4}{7}\right)=0\)
\(x-\frac{8}{15}=-\frac{2}{3}\) \(\frac{3}{5}.x+\frac{4}{7}=0\)
\(x=-\frac{2}{3}+\frac{8}{15}\) \(\frac{3}{5}.x=-\frac{4}{7}\)
\(x=-\frac{2}{15}\) \(x=-\frac{20}{21}\)
a) 12. \(\frac{4}{9}\)+\(\frac{4}{3}\)=\(\frac{16}{3}\)+\(\frac{4}{3}\)=\(\frac{20}{3}\)
b) (\(\frac{-5}{7}\)) . (12,5+1,5)= (\(\frac{-5}{7}\)).14=-10
a) \(12.\left(-\frac{2}{3}\right)^2+\frac{4}{3}=12.\frac{4}{9}+\frac{4}{3}=\frac{16}{3}+\frac{4}{3}=\frac{20}{3}\)
b) \(12,5.\left(-\frac{5}{7}\right)+1,5.\left(-\frac{5}{7}\right)=-\frac{5}{7}.\left(12,5+1,5\right)=-\frac{5}{7}.14=-10\)
c) \(1:\left(\frac{2}{3}-\frac{3}{4}\right)^2=1:\left(-\frac{1}{12}\right)^2=1:\frac{1}{144}=1.144=144\)
d) \(15.\left(-\frac{2}{3}\right)^2-\frac{7}{3}=15.\frac{4}{9}-\frac{7}{3}=\frac{20}{3}-\frac{7}{3}=\frac{13}{3}\)
e) \(\frac{1}{2}\sqrt{64}-\sqrt{\frac{4}{25}}+\left(-1\right)^{2007}=\frac{1}{2}.8-\frac{2}{5}+\left(-1\right)=4-\frac{2}{5}-1=\frac{13}{5}\)
a) \(\frac{\left(-1\right)}{4}^2+\frac{3}{8}.\left(\frac{-1}{6}\right)-\frac{3}{16}:\left(\frac{-1}{2}\right)=\left(\frac{-1}{4}\right)^2+\left(\frac{-3}{68}\right)-\left(\frac{-3}{8}\right)=\left(\frac{1}{16}\right)+\left(\frac{-3}{68}\right)-\left(\frac{-3}{8}\right)=\frac{5}{272}-\left(\frac{-3}{8}\right)=\frac{107}{272}\)
a)
\(=\frac{3}{5}.\frac{3}{7}+\frac{3}{5}.\frac{4}{7}-\left(1+\frac{3}{5}\right)\)
\(=\frac{3}{5}\left(\frac{3}{7}+\frac{4}{7}\right)-1-\frac{3}{5}\)
\(=\frac{3}{5}-1-\frac{3}{5}\)
\(=-1\)
b) \(=\frac{2^2.5.7.5^2.7^3}{2^2.5^2.7^{2.2}}\)
\(=\frac{2^2.5^{1+2}.7^{3+1}}{2^2.5^2.7^4}=\frac{2^2.5^3.7^4}{2^2.5^2.7^4}=2^{2-2}.5^{3-2}.7^{4-4}=2^0.5^1.7^0=1.5.1=5\)
\(A=\left[0,8\cdot7+(0,8)^2\right]\cdot\left[1,25\cdot7-\frac{4}{5}\cdot1,25\right]-47,86\)
\(=0,8\cdot(7+0,8)\cdot1,25\cdot(7-0,8)-47,86\)
\(=0,8\cdot7,8\cdot1,25\cdot6,2-47,86\)
\(=48,36-47,86=0,5\)
\(B=\frac{(1,09-0,29)\cdot\frac{5}{4}}{(18,9-16,65)\cdot\frac{8}{9}}=\frac{0,8\cdot1,25}{2,25\cdot\frac{8}{9}}=\frac{1}{2}\)
\(A:B=0,5:\frac{1}{2}=\frac{1}{2}:\frac{1}{2}=\frac{1}{2}\cdot2=1\)
A gấp 1 lần B
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