Question

\(\frac{-9}{12}-\left(\frac{-35}{42}\right)\)

Answer 1

=-63/84+70/84

=70+(-63)/84

=-7/84=-1/12

Answer 2

Chọn phương án chính xác cho phép tính sau: \(-\frac{9}{12}-\left(\frac{-35}{42}\right)\) = ?

A.  \(\frac{-9}{12}-\left(\frac{-35}{42}\right)=\frac{-9}{12_{\left(42\right)}}+\frac{35}{42_{\left(12\right)}}=\frac{-378+420}{504}=\frac{42}{504}=\frac{1}{12}\)

B. \(\frac{-9}{12}-\left(\frac{-35}{42}\right)=-\frac{9}{12}+\frac{35}{42}=-\frac{9}{12_{\left(7\right)}}+\frac{5}{7_{\left(12\right)}}=\frac{-63+60}{84}=-\frac{3}{84}=\frac{-1}{12}\)