\(\dfrac{10}{20}\) + \(\dfrac{7}{20}\) = \(\dfrac{17}{20}\)
\(\dfrac{8}{15}\) . \(\dfrac{15}{12}\) = \(\dfrac{8}{12}\) = \(\dfrac{2}{3}\)
Bài 1: Tính
1/2 + 7/20= 10/20 + 7/20 = 17/20
8/15 x 15/1= 2/3
\(\dfrac{1}{2}+\dfrac{7}{20}=\dfrac{10}{20}+\dfrac{7}{20}=\dfrac{17}{20}\)
\(\dfrac{8}{15}\times\dfrac{15}{12}=\dfrac{120}{180}=\dfrac{2}{3}\)
Bài 2 :
\(18\times\dfrac{5}{3}=30\)
\(60\times\dfrac{5}{3}=100\)
\(\dfrac{18}{45}\times\dfrac{5}{3}=\dfrac{2}{3}\)