Question

Tính bằng cách thuận tiện : 4/7 x 5/12 + 4/7 x 7/12 + 4/7

 

Answer 1

(5/12+7/12) nhân 4/7=4/7

hok tốt

Answer 2

\(\frac{4}{7}.\frac{5}{12}+\frac{4}{7}.\frac{7}{12}+\frac{4}{7}\)

\(=\frac{4}{7}.\left(\frac{5}{12}+\frac{7}{12}+1\right)\)

\(=\frac{4}{7}\left(\frac{12}{12}+1\right)\)

\(=\frac{4}{7}.2\)

\(=\frac{8}{7}\)

Answer 3

\(\frac{4}{7}\times\frac{5}{12}+\frac{4}{7}\times\frac{7}{12}+\frac{4}{7}\)

\(=\frac{4}{7}\times\frac{5}{12}+\frac{4}{7}\times\frac{7}{12}+\frac{4}{7}\times1\)

\(=\frac{4}{7}\times\left(\frac{5}{12}+\frac{7}{12}+1\right)\)

\(=\frac{4}{7}\times\left(\frac{12}{12}+1\right)\)

\(=\frac{4}{7}\times\left(1+1\right)\)

\(=\frac{4}{7}\times2=\frac{4}{7}\times\frac{2}{1}=\frac{8}{7}\)

(đúng thì k, sai thì thôi)

Answer 4

Tuy bạn sai nhưng bạn Quỳnh Anh làm đúng hơn nhé!!!!!