Question

a) 8 phần 15 + 5=
b) 4 - 7 phần 3 = 
c 1 phần 2 x 8 = 
d) 4 phần 9 : 2 =
e) 3 phần 14 : + 1 phần 2 =

Answer 1

a) 8/15 + 5

= 8/15 + 5/1

= (8 + 5*15)/15

= (8 + 75)/15

= 83/15

b) 4 - 7/3

= 4/1 - 7/3

= (4*3 - 7)/3

= (12 - 7)/3

= 5/3

c) 1/2 * 8

= 1/2 * 8/1

= (1*8)/(2*1)

= 8/2

= 4

d) 4/9 : 2

= 4/9 * 1/2

= (4*1)/(9*2)

= 4/18

= 2/9

e) 3/14 + 1/2

= (3*2 + 1*14)/(14*2)

= (6 + 14)/28

= 20/28

= 5/7

Answer 2

a) \(\dfrac{8}{15}+5=\dfrac{8}{15}+\dfrac{75}{15}=\dfrac{83}{15}\)

b) \(4-\dfrac{7}{3}=\dfrac{12}{3}-\dfrac{7}{3}=\dfrac{5}{3}\)

c) \(\dfrac{1}{2}\times8=\dfrac{1\times8}{2}=\dfrac{8}{2}=4\)

d) \(\dfrac{4}{9}:2=\dfrac{4}{9}\times\dfrac{1}{2}=\dfrac{4}{18}=\dfrac{2}{9}\)

e) ( Vì bạn ghi dấu không rõ nên mik làm 2 cách, trúng câu nào thì bạn ghi vô nhé. )

+) \(\dfrac{3}{14}:\dfrac{1}{2}=\dfrac{3}{14}\times2=\dfrac{3}{7}\)

+) \(\dfrac{3}{14}+\dfrac{1}{2}=\dfrac{3}{14}+\dfrac{7}{14}=\dfrac{10}{14}=\dfrac{5}{7}\)

Chúc bạn học tốt

Answer 3

a) 8/15 + 5

= 8/15 + 5/1

= (8 + 5*15)/15

= (8 + 75)/15

= 83/15

b) 4 - 7/3

= 4/1 - 7/3

= (4*3 - 7)/3

= (12 - 7)/3

= 5/3

c) 1/2 * 8

= 1/2 * 8/1

= (1*8)/(2*1)

= 8/2

= 4

d) 4/9 : 2

= 4/9 * 1/2

= (4*1)/(9*2)

= 4/18

= 2/9

e) 3/14 + 1/2

= (3*2 + 1*14)/(14*2)

= (6 + 14)/28

= 20/28

= 5/7