bài 1
a)\(=\dfrac{16}{40}+\dfrac{15}{40}=\dfrac{31}{40}\)
b)\(=\dfrac{7}{6}-\dfrac{4}{6}=\dfrac{3}{6}=\dfrac{1}{2}\)
c)\(=\dfrac{30}{9}=\dfrac{10}{3}\)
d)\(=\dfrac{8}{5}\times\dfrac{7}{4}=\dfrac{14}{5}\)
bài 1
a) 2/5 + 3/8 = 31/40
b) 7/6 - 2/3 = 1/2
c) 5/9 x 6 = 10/3
d) 8/5 : 4/7 = 14/5
Bài 2
a) 4/5 + x = 5/6
x = 5/6 - 4/5
x = 1/30
b) x : 7/10 = 5
x = 7/10 x 5
x = 7/2
bài 2
a)\(x=\dfrac{5}{6}-\dfrac{4}{5}=\dfrac{25}{30}-\dfrac{24}{30}=\dfrac{1}{30}\)
b)\(x=5:\dfrac{7}{10}=5\times\dfrac{10}{7}=\dfrac{50}{7}\)
bài 2
a)\(x=\dfrac{5}{6}-\dfrac{4}{5}=\dfrac{25}{30}-\dfrac{24}{30}=\dfrac{1}{30}\)
b)\(x=5\times\dfrac{10}{7}=\dfrac{50}{7}\)
