Question

BT1: Tính giá trị của biểu thức:

3) \(\dfrac{5}{3}.\dfrac{11}{2}+\dfrac{1}{4}\)

4) \(\left(\dfrac{5}{2}-\dfrac{1}{3}\right).\dfrac{9}{2}-\dfrac{6}{7}\)

Answer 1

3) \(\dfrac{5}{3}.\dfrac{11}{2}+\dfrac{1}{4}\)

\(=\dfrac{5.11}{3.2}+\dfrac{1}{4}\)\

\(=\dfrac{55}{6}+\dfrac{1}{4}\)

\(=\dfrac{220}{24}+\dfrac{6}{24}\)

\(=\dfrac{226}{24}\)

\(=\dfrac{113}{12}\)

4) \(\left(\dfrac{5}{2}-\dfrac{1}{3}\right).\dfrac{9}{2}-\dfrac{6}{7}\)

\(=\left(\dfrac{15}{6}-\dfrac{2}{6}\right).\dfrac{9}{2}-\dfrac{6}{7}\)

\(=\dfrac{13}{6}.\dfrac{9}{2}-\dfrac{6}{7}\)

\(=\dfrac{13.9}{6.2}-\dfrac{6}{7}\)

\(=\dfrac{117}{12}-\dfrac{6}{7}\)

\(=\dfrac{39}{4}-\dfrac{6}{7}\)

\(=\dfrac{273}{28}-\dfrac{24}{28}\)

\(=\dfrac{249}{28}\)