Question

Tính nhẩm:

2/7+3/7=.......                 3/5+2=.......                 ² 3/5-2=.......                 2-3/5=.......  

Answer 1

\(\dfrac{2}{7}+\dfrac{3}{7}=\dfrac{5}{7}\)

\(\dfrac{3}{5}+2=\dfrac{13}{5}\)

\(\dfrac{3}{5}-2=\dfrac{-7}{5}\)

\(2-\dfrac{3}{5}=\dfrac{7}{5}\)

Answer 2

2/7 + 3/7 = 5/7

3/5 + 2 = 3/5 + 10/5 = 13/5

2 - 3/5 = 10/5 - 3/5 = 7/5

Answer 3

trả lời lại nha mn

Answer 4

\(a,=\dfrac{2+3}{7}=\dfrac{5}{7}\\ b,=\dfrac{3}{5}+\dfrac{2.5}{5}=\dfrac{3+10}{5}=\dfrac{13}{5}\\ c,=\dfrac{23}{5}-2=\dfrac{23-10}{5}=\dfrac{13}{5}\\ d,2-\dfrac{3}{5}=\dfrac{2.5-3}{5}=\dfrac{7}{5}\)

Answer 5

\(\dfrac{2}{7}+\dfrac{3}{7}=\dfrac{5}{7},\dfrac{3}{5}+2=\dfrac{3}{5}+\dfrac{2}{1}=\dfrac{3}{5}+\dfrac{10}{5}=\dfrac{13}{5},\dfrac{23}{5}-2=\dfrac{23}{5}-\dfrac{2}{1}=\dfrac{23}{5}-\dfrac{10}{5}=\dfrac{13}{5},2-\dfrac{3}{5}=\dfrac{2}{1}-\dfrac{3}{5}=\dfrac{10}{5}-\dfrac{3}{5}=\dfrac{7}{5}\)