Question

\(\frac{-1}{6},\frac{1}{-9},\frac{-1}{12}\)tìm mẫu chung luôn nhé

Answer 1

\(\frac{1}{-9}=\frac{-1}{9}\)

6 = 2.3

9 = 3²

12 = 2².3

BCNN (6;9;12) = 2².3² = 36

\(\frac{-1}{6}=\frac{-1.6}{6.6}=\frac{-6}{36}\\ \frac{-1}{9}=\frac{-1.4}{9.4}=\frac{-4}{36}\\ \frac{-1}{12}=\frac{-1.3}{12.3}=\frac{-3}{36}\)

Answer 2

\(\frac{-1}{6},\frac{1}{-9},\frac{-1}{12}\)

\(\Rightarrow\frac{-1}{6},\frac{-1}{9},\frac{-1}{12}\)

Phân tích ra:

\(6=2.3\)

\(9=3^2\)

\(12=2^2.3\)

\(\Rightarrow BCNN\left(9;9;12\right)=2^2.3^2=36\)

\(\frac{-1}{6}=\frac{-1.6}{6.6}=\frac{-6}{36}\)

\(\frac{-1}{9}=\frac{-1.4}{9.4}=\frac{-4}{36}\)

\(\frac{-1}{12}=\frac{-1.3}{12.3}=\frac{-3}{36}\)