5[(85 - 35 : 7) : 8 + 90] - 50
= 5[(85 - 5) : 8 + 90] - 50
= 5.[ 80 : 8 + 90] - 50
= 5.[ 10 + 90 ] - 50
= 5. 100 - 50
= 500 - 50
= 450
5[(85 - 35 : 7) : 8 + 90] - 50
= 5[(85 - 5) : 8 + 90] - 50
= 5.[ 80 : 8 + 90] - 50
= 5.[ 10 + 90 ] - 50
= 5. 100 - 50
= 500 - 50
= 450