a: \(8\frac{3}{19}\cdot5\frac14+3\frac{16}{19}\cdot5\frac14\)
\(=5\frac14\left(8+\frac{3}{19}+3+\frac{16}{19}\right)\)
\(=\frac{21}{4}\cdot10=21\cdot\frac52=\frac{105}{2}\)
TA có: \(\left(2\frac{14}{17}-2\frac{1}{34}\right)\cdot34\)
\(=\left(2+\frac{14}{17}-2-\frac{1}{34}\right)\cdot34\)
\(=\left(\frac{28}{34}-\frac{1}{34}\right)\cdot34=27\)
TA có: \(A=\frac{8\frac{3}{19}\cdot5\frac14+3\frac{16}{19}\cdot5\frac14}{\left(2\frac{14}{17}-2\frac{1}{34}\right)\cdot34}:\frac{7}{24}\)
\(=\frac{105}{2\cdot27}\cdot\frac{24}{7}=\frac{105}{7}\cdot\frac{24}{2\cdot27}=15\cdot\frac{8}{9\cdot2}=\frac{15}{9}\cdot4=\frac53\cdot4=\frac{20}{3}\)
