Question

câu 8: tính                                                                                                                a) 7/15 + 4/5                  b) 4/5 x 5/8                c) 2/3 - 3/8                  d) 1/2 : 2/5

Answer 1

a) 7/15 + 4/5 = 7/15 + 12/15 = 19/15 

b) 4/5 x 5/8= 1/2

c) 2/3 - 3/8= 16/24 - 9/24 = 7/24

d) 1/2 : 2/5= 1/2 x 5/2= 5/4

Answer 2

a) \(\dfrac{7}{15}+\dfrac{4}{5}=\dfrac{7}{15}+\dfrac{12}{15}=\dfrac{19}{15}\)

b) \(\dfrac{4}{5}\times\dfrac{5}{8}=\dfrac{20}{40}=\dfrac{1}{2}\)

c) \(\dfrac{2}{3}-\dfrac{3}{8}=\dfrac{16}{24}-\dfrac{9}{24}=\dfrac{7}{24}\)

d) \(\dfrac{1}{2}:\dfrac{2}{5}=\dfrac{1}{2}\times\dfrac{5}{2}=\dfrac{5}{4}\)

Answer 3

a) 7/15 + 4/5 = 7/15 + 12/15 = 19/15 

b) 4/5 x 5/8= 1/2

c) 2/3 - 3/8= 16/24 - 9/24 = 7/24

d) 1/2 : 2/5= 1/2 x 5/2= 5/4

Answer 4

a) 7/15 + 4/5 = 7/15 + 12/15 = 19/15 

b) 4/5 x 5/8= 1/2

c) 2/3 - 3/8= 16/24 - 9/24 = 7/24

d) 1/2 : 2/5= 1/2 x 5/2= 5/4