(77 x 54 - 54 x 75): 54 + 720 : 36 x 2
=[54*(77-75)]:54+720:36*2
=[54*2]:54+20*2
=[54:54]*2+40
=2+40
=42
(77 x 54 - 54 x 75): 54 + 720 : 36 x 2
=[54*(77-75)]:54+720:36*2
=[54*2]:54+20*2
=[54:54]*2+40
=2+40
=42
{ 77 x 54 - 54 x 75 } : 54 + 720 : 36 x 2
= 54 x { 77 - 75 } : 54 + 720 : 36 x 2
= { 54 x 2 } : 54 x 20 x 2
= { 54 : 54 } x 2 + 40
= 2 + 40
= 42