1. Determine o valor das seguintes expressões:a) 4 + 7.3-15: 5-7 =b) 124[35-(10+ 2) + 2) =c) [(18+3.2):8–5.3] : 6 =d) 2.(4-3){2-[1+ 4.(6-4) 18:2).(1-3) +101) =e) - 300 + 150 + 800-950 =f) 700 + (-300) + 2000 - (-1200) - 200 =g) 7+5.8-2.4 =h) 8+ 7.4 -3.5+ 7 =i) (7 + 3)(7-3)-[2.(4 +1)-3(4 - 1)] =1) 8+[(255-21.3):6] =
Soluções para a tarefa
a) 4 + 7 . 3 - 15 : 5 - 7
= 4 + 21 - 15 : - 2
= 4 + 6 : - 2
= 8 : - 2
= - 4
b) 124 . [ 35 - ( 10 + 2 ) + 2 ]
= 124 . ( 35 - 8 + 2 )
= 4 340 - 992 + 248
= 3 348 + 248
= 3 596
c) [ ( 18 + 3 . 2 ) : 8 – 5 . 3 ] : 6
= [ ( 18 + 6 ) : 8 - 15 ] : 6
= ( 24 : 8 - 15 ) : 6
= ( 3 - 15 ) : 6
= - 12 : 6
= - 2
d) 2 . (4 - 3) . {2 - [1 + 4. (6 - 4) + 18 : 2) . ( 1 - 3) + 101)
= 8 - 6 . [ 2 - ( 1 + 24 - 16 + 9 ) . ( - 2 ) + 101 ]
= 2 . ( 2 - 1 - 24 + 16 - 9 ) . ( - 2 ) + 101
= 4 - 2 - 48 + 32 - 18 . ( - 2 ) + 101
= 2 - 16 + 36 + 101
= 2 + 20 + 101
= 22 + 101
= 123
e) - 300 + 150 + 800 - 950
= - 150 - 150
= - 300
f) 700 + (-300) + 2000 - (-1200) - 200
= 700 - 300 + 2000 + 1200 - 200
= 400 + 3200 - 200
= 400 + 3000
= 3400
g) 7 + 5 . 8 - 2 . 4
= 7 + 40 - 8
= 47 - 8
= 39
h) 8 + 7 . 4 - 3 . 5 + 7
= 8 + 28 - 15 + 7
= 36 - 8
= 28
i) (7 + 3) . (7 - 3) - [2 . (4 +1) - 3 . (4 - 1) ]
= 49 - 21 + 21 - 9 - ( 8 + 2 ) - 12 + 3
= 49 - 9 - 8 + 2 - 12 + 3
= 40 - 6 - 12 + 3
= 40 - 18 + 3
= 22 + 3
= 25
j) 8 + [ (255 - 21 . 3) : 6 ]
= 8 + [ (255 - 63) : 6 ]
= 8 + ( 192 : 6 )
= 8 + 32
= 40