Respuesta :

first do (27/9) which comes out to 3, then it's (10-3) which is 7, then 7*3 so your answer is 21 

3[10-(27/9)]
3[10-3]
3[7]
21
 3[10-(27÷9)]
     3(10-3)
        3x7
         21

 3[10-(27÷9)]= 21