-575/756                    

Bạn nhóm ra tương tự như 2 bài trước thôi

\(H=\frac{\frac{15}{8}-\frac{15}{6}-\frac{15}{32}+\frac{15}{63}}{3-\frac{3}{2}-\frac{3}{4}+\frac{3}{8}}\)

\(H=\frac{15\left(\frac{1}{8}-\frac{1}{6}-\frac{1}{32}+\frac{1}{63}\right)}{3\left(1-\frac{1}{2}-\frac{1}{4}+\frac{1}{8}\right)}\)

\(H=\frac{15\left[\left(\frac{1}{8}-\frac{1}{32}\right)-\frac{1}{6}+\frac{1}{63}\right]}{3\left[\left(1+\frac{1}{8}\right)-\frac{1}{2}-\frac{1}{4}\right]}\)

\(H=\frac{15\left[\frac{3}{32}-\frac{1}{6}+\frac{1}{63}\right]}{3\left[\frac{9}{8}-\frac{4}{8}-\frac{2}{8}\right]}\)

\(H=\frac{15\left[\frac{-7}{96}+\frac{1}{63}\right]}{3\cdot\frac{3}{8}}\)

\(H=\frac{15\left[\frac{-147}{2016}+\frac{32}{2016}\right]}{\frac{9}{8}}\)

\(H=\frac{15\cdot\frac{-115}{2016}}{\frac{9}{8}}\)

\(H=\frac{15\cdot\frac{-115}{2016}-\frac{2153}{2016}+\frac{2153}{2016}}{\frac{9}{8}}\)

\(H=\frac{15\cdot\frac{-2268}{2016}+\frac{2153}{2016}}{\frac{9}{8}}\)

\(H=\frac{15\cdot\frac{-9}{8}}{\frac{9}{8}}+\frac{\frac{2153}{2016}}{\frac{9}{8}}\)

\(H=\frac{-15\cdot\frac{9}{8}}{\frac{9}{8}}+\frac{\frac{2268}{2016}}{\frac{9}{8}}-\frac{\frac{115}{2016}}{\frac{9}{8}}\)

\(H=-15+1-0,0507054674 \)

\(H=-14-0,0507054674 \)

\(H=-14,0507055\)

\(=\left(\frac{15}{8}-\frac{15}{6}-\frac{15}{32}+\frac{15}{63}\right):\left(3-\frac{3}{2}-\frac{3}{4}+\frac{3}{8}\right)\)

\(=\left(\frac{3780}{2016}-\frac{5040}{2016}-\frac{945}{2016}+\frac{480}{2016}\right):\left(\frac{24}{8}-\frac{12}{8}-\frac{6}{8}+\frac{3}{8}\right)\)

\(=\frac{-575}{672}:\frac{9}{8}=\frac{-575}{672}.\frac{8}{9}=\frac{-575}{756}\)

\(\frac{-15}{4}\times\frac{9}{11}+\frac{15}{4}\times\frac{15}{11}-\frac{15}{4}\times\frac{6}{11}\)

\(=\frac{15}{4}\times\left(\frac{-9}{11}+\frac{15}{11}-\frac{6}{11}\right)\)

\(=\frac{15}{4}\times0\)

\(=0\)

\(=\frac{15}{4}\times\left(-\frac{9}{11}\right)+\frac{15}{4}\times\frac{15}{11}+\frac{15}{4}\times\left(-\frac{6}{11}\right)\)

\(=\frac{15}{4}\times\left(-\frac{9}{11}+\frac{15}{11}+\left(-\frac{6}{11}\right)\right)\)

\(=\frac{15}{4}\times0\)

\(=0\)

a: \(=\left(\dfrac{2}{18}-\dfrac{15}{18}-\dfrac{72}{18}\right):\left(\dfrac{21}{36}-\dfrac{1}{36}-\dfrac{360}{36}\right)\)

\(=\dfrac{-85}{18}:\dfrac{-170}{18}\)

\(=\dfrac{85}{170}=\dfrac{1}{2}\)

b: \(=\left(\dfrac{5}{8}-\dfrac{5}{6}-\dfrac{5}{32}+\dfrac{5}{64}\right):\left(1-\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{8}\right)\)

\(=\dfrac{-55}{192}:\dfrac{3}{8}=\dfrac{-55}{192}\cdot\dfrac{8}{3}=-\dfrac{55}{72}\)