Question

Answer 1

=7/15+12/15

=19/15

Answer 2

a 19/15

 b 1/30

 c1/10

Answer 3

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

b) \(\dfrac{5}{6}-\dfrac{1}{5}\times4=\dfrac{5}{6}-\dfrac{4}{5}=\dfrac{25}{30}-\dfrac{24}{30}=\dfrac{1}{30}\)

c) \(\dfrac{9}{8}-\dfrac{9}{8}\div\dfrac{5}{4}=\dfrac{9}{8}-\left(\dfrac{9}{8}\times\dfrac{4}{5}\right)=\dfrac{9}{8}-\dfrac{36}{40}=\dfrac{9}{40}\)

Answer 4

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

`b)` \(\dfrac{5}{6}-\dfrac{1}{5}\times4=\dfrac{5}{6}-\dfrac{4}{5}=\dfrac{25}{30}-\dfrac{24}{30}=\dfrac{1}{30}\)

`c)` \(\dfrac{9}{8}-\dfrac{9}{8}:\dfrac{5}{4}=\dfrac{9}{8}-\dfrac{9}{10}=\dfrac{90}{80}-\dfrac{72}{80}=\dfrac{18}{80}=\dfrac{9}{40}\)

Answer 5

a) đề bài

= 7/15 + 12/15

=19/15

b)đề bài

= 5/6 - 1/5 x 4/1

= 5/6 - 4/5

= 25/30 - 24/30

= 1/30

c)đề bài

= 9/8 - 9/8 x 4/5

= 9/8 - 9/10

= 45/40 - 36/40

= 9/40

nhớ tick cho tui nha!