Question

1.tính 

18/17:9             

8/5-18/27         

 2/7+5/9

Answer 1

\(\dfrac{18}{17}:9=\dfrac{18}{17}\times\dfrac{1}{9}=\dfrac{18}{153}=\dfrac{2}{17}\)

\(\dfrac{8}{5}-\dfrac{18}{27}=\dfrac{216}{135}-\dfrac{90}{135}=\dfrac{126}{135}=\dfrac{14}{15}\)

\(\dfrac{2}{7}+\dfrac{5}{9}=\dfrac{18}{63}+\dfrac{35}{63}=\dfrac{53}{63}\)

Answer 2

`18/17:9 = 18/17 xx 1/9 =  2/17 `

`8/5-18/27     = 216/135 - 90/135 = 126/135 = 14/15 `    

` 2/7+5/9 = 18/63 + 35/63 =53/63`