Efetue as adiçoes e subtraçoes a seguir.
a)4/7 + 2/7 =
b)8/5 - 3/5 =
c)3/10 + 1/4
d)4/5 - 2/3 =
e)5/8 - 1/4 =
f)1 1/4 + 1/6
g)1 3/10 - 8/9=
h)3/25 + 2/5 =
i)3/4 + (4/5 - 3/10)=
j)5/8 - 3/8 - 1/8
com as contas por favor!
Soluções para a tarefa
a)4/7 + 2/7 = (4+2)/7 = 7/7 = 1
b)8/5 - 3/5 = (8-3)/5 = 5/5 = 1
c)3/10 + 1/4 = (12+11)/40 = 33/40
d)4/5 - 2/3 = (12-10)/15 =2/15
e)5/8 - 1/4 = (5-2)/8 =3/8
f) 1 1/4 + 1/6 = (33+2)/12 = 31/12
g) 1 3/10 - 8/9= ( 117-80)/90 = 37/90
h) 3/25 + 2/5 = (3+10)/25 = 13/25
i) 3/4 + (4/5 - 3/10) = 3/4 + [(8-3)/10] = 3/4 + [5/10] = 3/4+1/5 = (15+4)/20 = 19/20
j) 5/8 - 3/8 - 1/8 = (5-3-1)/8 = 1/8
a) 4/7 + 2/7 = 6/7
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b) 8/5 - 3/5 = 5/5 = 1
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c) 3/10 + 1/4 =
mmc (4, 10) = 20
6 + 5/20 = 11/20
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d) 4/5 - 2/3 =
mmc (5,3) = 15
12 - 10/15 = 2/15
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e) 5/8 - 1/4 =
mmc (8,4) = 8
5 - 2/8 = 3/8
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f) 1 1/4 + 2 1/6 =
mmc de (4,6) = 12
5/4 + 13/6 = 15 + 26/ 12 = 41/12
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g) 1 3/10 - 8/9 =
mmc de (9,10) = 90
9 x 13/90 - 10 x 8/90 = 117/90 - 80/90 = 37/90
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h) 3/25 + 2/5 =
mmc de (25,5) = 25
3 + 10/25 = 13/25
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i) 3/4 + (4/5 - 3/10) =
primeiro descobrir o que está em parênteses!
4/5 - 3/10 = 8 - 3/10 = 5/10
3/4 + 5/10 = 15 + 10/20 = 25/20 (dividindo por 5) = 5/4
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j) 5/8 - 3/8 - 1/8 =
os denominadores são iguais (8), efetuar as operações com os numeradores.
(5-3-1)/8 = 1/8