a) 151 - 291 : 288 + 12 . 3
= 151 - 23 + 1 . 3
= 151 - 8 + 3
= 143 + 3
= 146
b) 1449 - { [ ( 216 +184 ) : 8 ] . 9 }
= 1449 - { [ 400 : 8 ] . 9 }
= 1449 - { 50 . 9 }
= 1449 - 450
= 999
c) 23 . 75 + 25 . 23 + 180
= 23 . ( 75 + 25 ) + 180
= 23 . 100 + 180
= 2300 + 180
= 2480
d) 80 - ( 4 . 52 - 3 . 23 )
= 80 - ( 4 . 25 - 3 . 8 )
= 80 - ( 100 - 24 )
= 80 - 76
= 4
151-291:288+12*3=151-23+1*3=151-8+1*3=146
b, 1449-{[(216+184):8]*9}=1449-{[400:8]*9}=1449-{50*9} = 1449-450=999
c,23*75+25*23+180=25*(75+23)+180=2630
d,80-(4*52-3*23)=80-(4*25-3*8)=4