Question

Answer 1

Bài 8 : = \(\dfrac{3}{12}+\dfrac{4}{12}\) = \(\dfrac{1}{4}+\dfrac{1}{3}\).

Bài 9 :

a, => x= \(\dfrac{1}{10}+\dfrac{1}{15}=\dfrac{3+2}{30}=\dfrac{5}{30}=\dfrac{1}{6}\)

 

Answer 2

`x - 1/15 = 1/10`

`=> x = 1/15 + 1/10`

`=> x = 3/30 + 2/30`

`=> x = 5/30 = 1/6`

`b)` ​`(-2)/15-x=(-3)/10`

`=>x=(-2)/15-((-3)/10)`

`=>x=(-2)/15+3/10`

`=>x=(-4)/30+9/30`

`=>x=1/6`

`c)x + 1/3 = 2/5 + {-1}/3`

$\Rightarrow$ `x + 1/3 = 1/15`

$\Rightarrow$ `x = 1/15 - 1/3`

$\Rightarrow$ `x = 1/15 - 5/15`

$\Rightarrow$ `x = {1-5}/15`

$\Rightarrow$ `x = -4/15`

`d)`  `3/7 - x = 1/4 - (-3/5)`

`=> 3/7 - x = 5/20 + 12/20`

`=> 3/7 - x = 17/20`

`=> x = 3/7 - 17/20`

`=> x = -59/140`