a) 6.15 = 2.45
\(\dfrac{6}{45}\) = \(\dfrac{2}{15}\);
\(\dfrac{15}{45}\) = \(\dfrac{2}{6}\);
\(\dfrac{15}{2}\) = \(\dfrac{45}{6}\);
\(\dfrac{6}{2}\) = \(\dfrac{45}{15}\).
b) -0,125.16 = 0,4. (-5)
\(\dfrac{-0,125}{-5}\) = \(\dfrac{0,4}{16}\);
\(\dfrac{16}{-5}\) = \(\dfrac{0,4}{-0,125}\);
\(\dfrac{16}{0,4}\) = \(\dfrac{-5}{-0,125}\);
\(\dfrac{-0,125}{0,4}\) = \(\dfrac{-5}{16}\).
lập được các tỉ lệ thức sau
\(\dfrac{6}{2}=\dfrac{45}{15};\dfrac{15}{2}=\dfrac{45}{6};\dfrac{2}{6}=\dfrac{15}{45};\dfrac{2}{15}=\dfrac{6}{45}\)