Question

Lập các phân số bằng nhau từ đẳng thức cho trước:
a) 2.3 = (-1).(-6)                   b) 2.4 = 1.8                     c) (-4).6 = 3.(-8)
d) 3.6 = 2.9                          e) (-6).(-5) = 3.10             f) 3.8 = 2.12

Answer 1

a: \(2\cdot3=\left(-1\right)\cdot\left(-6\right)\)

=>\(\dfrac{2}{-1}=\dfrac{-6}{3};\dfrac{2}{-6}=\dfrac{-1}{3};\dfrac{-1}{2}=\dfrac{3}{-6};\dfrac{-6}{2}=\dfrac{3}{-1}\)

b: \(2\cdot4=1\cdot8\)

=>\(\dfrac{2}{1}=\dfrac{8}{4};\dfrac{2}{8}=\dfrac{1}{4};\dfrac{1}{2}=\dfrac{4}{8};\dfrac{8}{2}=\dfrac{4}{1}\)

c: \(\left(-4\right)\cdot6=3\cdot\left(-8\right)\)

=>\(\dfrac{-4}{3}=\dfrac{-8}{6};\dfrac{-4}{-8}=\dfrac{3}{6};\dfrac{3}{-4}=\dfrac{6}{-8};\dfrac{-8}{-4}=\dfrac{6}{3}\)

d: \(3\cdot6=2\cdot9\)

=>\(\dfrac{3}{2}=\dfrac{9}{6};\dfrac{3}{9}=\dfrac{2}{6};\dfrac{2}{3}=\dfrac{6}{9};\dfrac{9}{3}=\dfrac{6}{2}\)

e: \(\left(-6\right)\cdot\left(-5\right)=3\cdot10\)

=>\(\dfrac{-6}{3}=\dfrac{10}{-5};\dfrac{-6}{10}=\dfrac{3}{-5};\dfrac{3}{-6}=\dfrac{-5}{10};\dfrac{10}{-6}=\dfrac{-5}{3}\)

f: \(3\cdot8=2\cdot12\)

=>\(\dfrac{3}{2}=\dfrac{12}{8};\dfrac{3}{12}=\dfrac{2}{8};\dfrac{2}{3}=\dfrac{8}{12};\dfrac{12}{3}=\dfrac{8}{2}\)