a: =126+74=200
b: \(=42\cdot16-42\cdot35-35\cdot16+42\cdot35=7\cdot16=112\)
a: = 126 + 74 = 200
b: = 42⋅16 − 42⋅35 − 35⋅16 + 42⋅35 = 7⋅16 = 112 nha
HT
a) ( - 87) + 126 + 187 + 74 b) 42 . ( 16 - 35) - 35 . ( 16 - 42)
= [ (-87) + 187] + ( 126 + 74) = 42 . ( - 19) - 35 . ( -26)
= 100 + 200 = ( - 798) - ( - 910)
= 300 = 112
c) 24 . 5 - [ 68 + 8 . ( 35 - 37)2] : 4
= 16 . 5 -[ 68 + 8. (-2)2] : 4
= 80 - [ 68 + 8 . 4 ] : 4
= 80 - [ 68 + 32 ] : 4
= 80 - 100 : 4
= 80 - 25
= 55
