Question

không dùng máy tính háy tính giá trị của biểu thức \(S=\dfrac{\dfrac{3}{13}-0,6+\dfrac{3}{7}+0,75}{\dfrac{11}{7}-2,2+\dfrac{11}{13}+2,75}\)

Answer 1

\(S=\dfrac{\dfrac{3}{13}-0,6+\dfrac{3}{7}+0,75}{\dfrac{11}{7}-2,2+\dfrac{11}{13}+2,75}\\ =S=\dfrac{\dfrac{3}{13}-\dfrac{3}{5}+\dfrac{3}{7}+\dfrac{3}{4}}{\dfrac{11}{7}-\dfrac{11}{5}+\dfrac{11}{13}+\dfrac{11}{4}}\\ =\dfrac{3\left(\dfrac{1}{13}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{4}\right)}{11\left(\dfrac{1}{7}-\dfrac{1}{5}+\dfrac{1}{13}+\dfrac{1}{4}\right)}\\ =\dfrac{3}{11}\)

Answer 2

`S = ((3/13 - 0,6 + 3/7 + 0,75))/(11/13 - 2,2 + 11/7 + 2,75)`

`= (3.(1/11 - 0,2 + 1/7 + 0,25))/(11(1/13 - 0,2 + 1/7 + 0,25))`

`= 3/11`.

Answer 3

`(3/13 - 0,6 + 3/7 + 0,75)/(11/7 - 2,2 + 11/13 + 2,75)`

` (3/13 - 3/5 + 3/7 + 3/4)/(11/7 - 11/5 + 11/13 + 11/4)`

` (3 . (1/13 + 1/5 + 1/7 + 1/4))/(11 . (1/7 - 1/5 + 1/13 + 11/4))`

` 3/11`

Answer 4

`(3/13 - 0,6 + 3/7 + 0,75)/(11/7 - 2,2 + 11/13 + 2,75)`

`= (3/13 - 3/5 + 3/7 + 3/4)/(11/7 - 11/5 + 11/13 + 11/4)`

`= (3 . (1/13 + 1/5 + 1/7 + 1/4))/(11 . (1/7 - 1/5 + 1/13 + 11/4))`

`= 3/11`