= 4/5 x ( 3/7 + 6/7 - 4/14 )
= 4/5 x ( 3/7 + 6/7 - 2/7 )
= 4/5 x 7/7
= 4/5
4/5 x 3/7 + 4/5 x 6/7 - 4/5 x 4/14
= 4/5 x ( 3/7 + 6/7 - 4/14)
= 4/5 x 1
= 4/5
= ( 3/7 + 6/7 - 4/14) × 4/5
= 1 × 4/5
= 4/5 => 0,8
4/5 x 3/7 + 4/5 x 6/7 - 4/5 x 4/14
= 4/5x (3/7+ 6/7- 4/14)
= 4/5 x 7/7 (bn có thể dùng 1 để dễ tính hơn nhé)
= 4/5
4/5 . 3/7 + 4/5 . 6/7 - 4/5 . 4/14
4/5 . ( 3/7 + 6/7 - 4/14)
4/5 . 1
4/5
\(\dfrac{4}{5}.\dfrac{3}{7}+\dfrac{4}{5}.\dfrac{6}{7}-\dfrac{4}{5}.\dfrac{4}{14}\)
\(=\dfrac{4}{5}.\left(\dfrac{3}{7}+\dfrac{6}{7}-\dfrac{4}{14}\right)\)
\(=\dfrac{4}{5}.\left(\dfrac{3}{7}+\dfrac{6}{7}-\dfrac{2}{7}\right)\)
\(=\dfrac{4}{5}.\left(\dfrac{9}{7}-\dfrac{2}{7}\right)\)
\(=\dfrac{4}{5}.\dfrac{7}{7}\)
\(=\dfrac{4}{5}\)
Lưu ý: Dấu "." là dấu "x" nhé! Hihi.