[12,(1) - 2,3(6)] : 4,(21)
=[12 + 0,(1) - 2,3 + 0,0(6)] : 4,(21)
=[12 + \(\frac{1}{9}\) - \(\frac{23}{10}\) + \(\frac{1}{10}\) . 0,(6)] : 4,(21)
=[\(\frac{12}{9}\) - \(\frac{23}{10}\) + \(\frac{1}{10}\) . \(\frac{6}{9}\)] : 4,(21)
=[\(\frac{4}{3}\)- \(\frac{23}{10}\) + \(\frac{1}{15}\)] : 4,(21)
=[\(\frac{4}{3}\)- \(\frac{71}{30}\)] : 4,(21)
= \(\frac{-31}{30}\): 4,(21)
= \(\frac{-31}{30}\): 4 + 0,(21)
= \(\frac{-31}{30}\): 4 + \(\frac{21}{99}\)
=\(\frac{-31}{30}\): \(\frac{139}{33}\)
= \(\frac{-341}{1390}\)
Mik làm bài toán mà ko biết có đúng hay ko mong các bn góp ý ^-^
đúng đấy bạn