Question

Tính hợp lí ( tính nhanh)

\(\dfrac{6}{13.}\dfrac{5}{7}+\dfrac{6}{13}.\dfrac{2}{7}+\dfrac{7}{13} \)

Answer 1

\(\dfrac{6}{13}.\dfrac{5}{7}+\dfrac{6}{13}.\dfrac{2}{7}+\dfrac{7}{13}=\dfrac{6}{13}.\left(\dfrac{5}{7}+\dfrac{2}{7}\right)+\dfrac{7}{13}=\dfrac{6}{13}.1+\dfrac{7}{13}=\dfrac{6}{13}+\dfrac{7}{13}=\dfrac{13}{13}=1\)

#Monster

Answer 2

\(\dfrac{6}{13}\).(\(\dfrac{2}{7}+\dfrac{5}{7}\))+\(\dfrac{7}{13}\)

\(\dfrac{6}{13}\).1+\(\dfrac{7}{13}\)

\(\dfrac{6}{13}\)+\(\dfrac{7}{13}\)

1

Answer 3

mik làm ở bài dưới rồi nha.

Answer 4

=\(\dfrac{6}{13}\).1+\(\dfrac{7}{13}\)

=1

Answer 5

=\(\dfrac{6}{13}\).(\(\dfrac{5}{7}\)+\(\dfrac{2}{7}\))+\(\dfrac{7}{13}\)

=\(\dfrac{6}{13}\).1+\(\dfrac{7}{13}\)

=\(\dfrac{6}{13}\)+\(\dfrac{7}{13}\)

=\(\dfrac{13}{13}\)=1

Answer 6

=  \(\dfrac{6}{13}\) + (\(\dfrac{5}{7}\)+\(\dfrac{2}{7}\))+\(\dfrac{7}{13}\)

= \(\dfrac{6}{13}\)+\(\dfrac{7}{7}\)+\(\dfrac{7}{13}\)

= \(\dfrac{6}{13}\)+1+\(\dfrac{7}{13}\)

= \(\dfrac{19}{13}\)+\(\dfrac{7}{13}\)

= \(\dfrac{26}{13}\)= 2

Answer 7

\(\dfrac{6}{13}\).\(\dfrac{5}{7}\)+\(\dfrac{6}{13}\).\(\dfrac{2}{7}\)+\(\dfrac{7}{13}\)=\(\dfrac{6}{13}\).(\(\dfrac{2}{7}\)+\(\dfrac{5}{7}\))+\(\dfrac{7}{13}\)=\(\dfrac{6}{13}\).1+\(\dfrac{7}{13}\)=\(\dfrac{6}{13}\)+\(\dfrac{7}{13}\)=\(\dfrac{13}{13}\)=1.