Question

Tính hộ mình câu b với. cảm ơn mn trước

Answer 1

b/\(\dfrac{3}{7}\times\dfrac{25}{19}-\dfrac{1}{7}\times\dfrac{18}{19}\)
\(=\dfrac{1}{7}\times3\times\dfrac{25}{19}-\dfrac{1}{7}\times\dfrac{18}{19}\)
\(=\dfrac{1}{7}\times\dfrac{75}{19}-\dfrac{1}{7}\times\dfrac{18}{19}\)
\(=\dfrac{1}{7}\times\left(\dfrac{75}{19}-\dfrac{18}{19}\right)\)
\(=\dfrac{1}{7}\times3\)
\(=\dfrac{3}{7}\)

Answer 2

=\(=\dfrac{1}{7\cdot19}\left(3\cdot25-18\right)=\dfrac{1}{7\cdot19}\cdot57=\dfrac{3}{7}\)