\(\left(\dfrac{1}{4}+\dfrac{1}{7}\right)\times\dfrac{1}{3}\\ =\left(\dfrac{7}{28}+\dfrac{4}{28}\right)\times\dfrac{1}{3}\\ =\dfrac{11}{28}\times\dfrac{1}{3}\\ =\dfrac{11}{84}\)
C1:
\(\left(\dfrac{1}{4}+\dfrac{1}{7}\right)\times\dfrac{1}{3}\\ =\left(\dfrac{7}{28}+\dfrac{4}{28}\right)\times\dfrac{1}{3}\\ =\dfrac{11}{28}\times\dfrac{1}{3}\\ =\dfrac{11}{84}\)
C2:
\(\left(\dfrac{1}{4}+\dfrac{1}{7}\right)\times\dfrac{1}{3}\\ =\dfrac{1}{4}\times\dfrac{1}{3}+\dfrac{1}{7}\times\dfrac{1}{3}\\ =\dfrac{1}{12}+\dfrac{1}{21}\\ =\dfrac{7}{84}+\dfrac{4}{84}\\ =\dfrac{11}{84}\)
(1/4 + 1/7) x 1/3
= 11/28 x 1/3
= 11/84
(1/4 + 1/7) x 1/3
= 1/4 x 1/3 + 1/7 x 1/3
= 1/12 + 1/21
= 11/84
(1/4 + 1/7) x 1/3
(7/28 + 4/28) x 1/3
11/28 x 1/3
11/84
Cách 1:
(1/4 + 1/7) x 1/3
= 11/28 x 1/3
= 11/84
Cách 2:
(1/4 + 1/7) x 1/3
= 1/4 x 1/3 + 1/7 x 1/3
= 1/12 + 1/21
= 11/84
