Question

1) Escreva na forma de fração irredutível
a) 1,2
b) 0,07
c)21,20
d)0,18181818.....
e)2,25
f)123,2

2 Escreva na forma decimal
A)13/100
B)-1/4
C)-13/2
D)8/5
E)-2/3
F)14/10

3 calcule o valor das expressões
A)[(-1)×(-2-1/4)]
B)(1/6+1/2)elevado a 2 +3/2

Answer 1

1)

a)

$1,2 = \frac{12}{10} = \frac{6}{5}$

b)

$0,07 = \frac{7}{100}$

c)

$21,20 = \frac{2120}{100} = \frac{106}{5}$

d)

$0,181818... = \frac{18}{99} = \frac{2}{11}$

e)

$2,25 = \frac{225}{100} = \frac{9}{4}$

f)

$123,2... = \frac{1232}{10} = \frac{616}{5}$

2)

a)

$\frac{13}{100} = 0,13$

b)

$- \frac{1}{4} = - 0,25$

c)

$- \frac{13}{2} = - 6,5$

d)

$- \frac{2}{3} = - 0,666...$

e)

$\frac{14}{10} = \frac{7}{5}$

3)

a)

$[(-1)×(-2- \frac{1}{4} )] = \\ [(-1)×( \frac{ - 8 - 1}{4} )] \\ = [(-1)×(- \frac{9}{4} )] = \frac{9}{4}$

b)

${ (\frac{1}{6} + \frac{1}{2} )}^{2} + \frac{3}{2} = {( \frac{1 + 3}{6} )}^{2} + \frac{3}{2}$

${ (\frac{1}{6} + \frac{1}{2} )}^{2} + \frac{3}{2} = \\ {( \frac{1 + 3}{6} )}^{2} + \frac{3}{2}$

${ (\frac{4}{6}) }^{2} + \frac{3}{2} \\ {( \frac{2}{3} )}^{2} + \frac{3}{2 } = \frac{4}{9} + \frac{3}{2} \: \\ = \frac{8 + 27}{18} = \\ \frac{35}{18}$