Respostas
Resposta:
Explicação passo-a-passo:
4)
a) 78 > 45, b) 37 > 0, c) -21 < 0, d) -42 < 58, e) -39 > -67
5)
a) -3, -2, -1, 0, 1, 4 , 5 b) está correta
6)
a) 2/5 = 0,4, b) 13/6 = 2,17, c) -50/8 = 6,25
7)
a) 1,3 = 13/10, b) 7,345 = 7345/1000, c) 764,34 = 76434/100
8)
a) 7/13 + 2/13 = (7 + 2)/13 = 9/13
b) 9/11 + 10/11 = (9 + 10)/11 = 19/11
c) 13/10 + 29/10 = (13 + 29)/10 = 42/10 = 21/5
d) 5/4 + 2/4 = (5 + 4)/4 = 9/4
9)
a) 1/3 + 2/5 = (5.1 + 3.2)/15 = (5 + 6)/15 = 11/15
b) 3/2 + 2/3 = (3.3 + 2.2)/6 = (9 + 4)/6 = 13/6
c) 2 - 7/6 +3/4 = (12.2 - 2.7 + 3.3)/12 = (24 - 14 + 9)/12 = 19/12
10)
a) 3/4.1/2 = 3.1/4.2 = 3/8
b) 2/3.1/4.8/5 = 2.1.8/3.4.5 = 2.1.2/3.1.5 = 4/15
c) 6/5.25/3.9/2 = 6.25.9/5.3.2 = 3.5.3/1.1.1=45/1 = 45
d) 9/7.3/4 = 9.3/7.4 = 27/28
11)
a) 4/5 : 2/3 = 4/5.3/2 = 4.3/5.2 = 2.3/5.1 = 6/5
b) 4/5 : 2 = 4/5.1/2 = 4.1/5.2 = 2.1/5.1 = 2/5
c) 13/49 : 39/14 = 13/49.14/39 = 13.14/49.39 = 1.2/7.3 = 2/21
d) 81/5 : 27/25 = 81/5.25/27 = 81.25/5.27 = 3.5/1.1 = 15
12)
b) - 5 + 2 = -3
c) +3 - 13 = -10
d) -2 - 7 = -9
e) +8 - 9 = -1