Question

Bài 2: Tính

a. 20/16 - 3/4

b. 30/45 - 2/5

c. 10/12 - 3/4

d. 12/9 - 1/4

Answer 1

a:=5/4-3/4=2/4=1/2

b: =2/3-2/5=10/15-6/15=4/15

c: =10/12-9/12=1/12

d: =4/3-1/4=16/12-3/12=13/12

Answer 2

\(a,=\dfrac{5}{4}-\dfrac{3}{4}=\dfrac{2}{4}\\ b,=\dfrac{30}{45}-\dfrac{18}{45}=\dfrac{12}{45}\\ c,=\dfrac{10}{12}-\dfrac{9}{12}=\dfrac{1}{12}\\ d,=1\dfrac{1}{12}\)

Answer 3

\(a,\dfrac{20}{16}-\dfrac{3}{4}=\dfrac{5}{4}-\dfrac{3}{4}=\dfrac{2}{4}=\dfrac{1}{2}\\ b,\dfrac{30}{45}-\dfrac{2}{5}=\dfrac{2}{3}-\dfrac{2}{5}=\dfrac{10}{15}-\dfrac{6}{15}=\dfrac{4}{15}\\ c,\dfrac{10}{12}-\dfrac{3}{4}=\dfrac{5}{6}-\dfrac{3}{4}=\dfrac{10}{12}-\dfrac{9}{12}=\dfrac{1}{12}\\ d,\dfrac{12}{9}-\dfrac{1}{4}=\dfrac{4}{3}-\dfrac{1}{4}=\dfrac{16}{12}-\dfrac{3}{12}=\dfrac{13}{12}\)

Answer 4

a) \(\dfrac{20}{16}-\dfrac{3}{4}=\dfrac{5}{4}-\dfrac{3}{4}=\dfrac{2}{4}=\dfrac{1}{2}\)

b) \(\dfrac{30}{45}-\dfrac{2}{5}=\dfrac{30}{45}-\dfrac{18}{45}=\dfrac{12}{45}\)

c) \(\dfrac{10}{12}-\dfrac{3}{4}=\dfrac{10}{12}-\dfrac{9}{12}=\dfrac{1}{12}\)

d) \(\dfrac{12}{9}-\dfrac{1}{4}=\dfrac{48}{36}-\dfrac{9}{36}=\dfrac{39}{36}=\dfrac{13}{12}\)