Question

5.calcule a fração
a)1/4 de 20
b)1/3de9
c)3/5de125
d)3/7de1/3
e)1/5de3/8
f)4/7de3/5



6.calcule a fração
a)2/3÷1/5
b)4/7÷3/9
c)3/4÷5/2
d)5/21÷3/7
e)10/3÷7/3
f)4/15÷2/35
g)7/10÷3/1
h)3/1÷7/10
i)1/5÷1/3
j)3/1÷1/9​

Answer 1

* De = x !

5)a)1/4 de 20

$\frac{1.20}{4} = \frac{20}{4} =5$

b)1/3de9

$\frac{1.9}{3} =\frac{9}{3} =3$

c)3/5de125

$\frac{3.125}{5} = \frac{375}{5} = 75$

d)3/7de1/3

$\frac{3.1}{7.3} = \frac{3}{21} = \frac{1}{7}$

e)1/5de3/8

$\frac{1.3}{5.8} =\frac{3}{40}$

f)4/7de3/5

$\frac{4.3}{7.5} =\frac{12}{35}$

*Divisão = repete a primeira fração e multiplica pelo inverso da segunda!

6)a)2/3÷1/5

$\frac{2.5}{3.1} = \frac{10}{3}$

b)4/7÷3/9

$\frac{4.9}{7.3} =\frac{36}{21} = \frac{12}{7}$

c)3/4÷5/2

$\frac{3.2}{4.5} = \frac{6}{20} =\frac{3}{10}$

d)5/21÷3/7

$\frac{5.7}{21.3} =\frac{35}{63}$

e)10/3÷7/3

$\frac{10.3}{3.7} = \frac{30}{21} = \frac{10}{7}$

f)4/15÷2/35

$\frac{4.35}{15.2} = \frac{140}{30} = \frac{14}{3}$

g)7/10÷3/1

$\frac{7.1}{10.3} =\frac{7}{30}$

h)3/1÷7/10

$\frac{3.10}{1.7} =\frac{30}{7}$

i)1/5÷1/3

$\frac{1.3}{5.1} =\frac{3}{5}$

j)3/1÷1/9

$\frac{3.9}{1.1} = \frac{27}{1} =27$

Espero ter ajudado!

Bons estudos!