Question

Calcule as expressões:

a)3/2+1/5-1/3=

b)3/4+2/5=

c)2/3-1/4=

ME AJUDEMMM PFVVV MARCO COMO MELHOR RESPOSTA PFVVVV GENTEEE
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Answer 1

Resposta:

a) 1/10 b) 1/4 c) 1/12

Resolução:

a) 3/2 + 1/5 - 1/3 =

mmc de 2, 5 e 3 = 2 x 3 x 5 = 30

(3+1-1) / 30 = 3/30 = 1/10

b)3/4+2/5=

mmc de 4 e 5 = 2 x 2 x 5 = 20

(3+2)/20 = 5/20 = 1/4

c)2/3-1/4=

mmc de 3 e 4 = 2 x 2 x 3 = 12

(2-1)/12 = 1/12

Answer 2

a) $\frac{3}{2} + \frac{1}{5} - \frac{1}{3} =$

mmc

2 , 5 , 3   2

1 , 5 , 3    3

   5 ,  1    5 = 2 . 3 . 5 = 30

    1

30 : 2 = 15 . 3 = $\frac{45}{30}$

30 : 5 = 6 . 1 = $\frac{6}{30}$

30 : 3 = 10 . 1 = $\frac{10}{30}$

$\frac{45}{30} + \frac{6}{30} - \frac{10}{30} = \frac{45+6-10}{30} = \frac{51-10}{30} =\frac{41}{30}$

b) $\frac{3}{4} + \frac{2}{5} =$

mmc

4 , 5    4

1 , 5     5 = 5 . 4 = 20

    1

20 : 4 = 4 . 3 = $\frac{12}{20}$

20 : 5 = 4 . 2 =$\frac{8}{20}$

$\frac{12}{20} + \frac{8}{20} = \frac{12+8}{20} = \frac{20}{20} = 1$

c) $\frac{2}{3} - \frac{1}{4} =$

mmc

3 , 4    3

1 ,  4    4 = 4 . 3 = 12

     1

12 : 3 = 4 . 2 = $\frac{8}{12}$

12 : 4 = 3 . 1 = $\frac{3}{12}$

$\frac{8}{12} - \frac{3}{12} = \frac{8 - 3}{12} = \frac{5}{12}$