Tìm số tự nhiên x biết
4 3/5 (4 3/5 là hỗn số) + 7/10 < x < 20/3
\(4\frac{3}{5}+\frac{7}{10}< x< \frac{20}{3}\)
\(\frac{23}{5}+\frac{7}{10}< x< \frac{20}{3}\)
\(\frac{53}{10}< x< \frac{20}{3}\)
\(\frac{159}{30}< x< \frac{200}{30}\)
Vậy \(x\in\left\{\frac{160}{30};\frac{161}{30};\frac{162}{30};...;\frac{198}{30};\frac{199}{30}\right\}\)
\(4\frac{3}{5}+\frac{7}{10}< x< \frac{20}{3}\)
\(\frac{4\times5+3}{5}+\frac{7}{10}< x>\frac{20}{3}\)
\(\frac{23}{5}+\frac{7}{10}< x< \frac{20}{3}\)
\(\frac{46}{10}+\frac{7}{10}< x< \frac{20}{3}\)
\(\frac{53}{10}< x< \frac{20}{3}\)
\(\frac{159}{30}< x< \frac{200}{30}\)
\(\Rightarrow x=\left\{160;161;162;......;199\right\}\)
Đổi: \(4\frac{3}{5}=\frac{23}{5}\)
Vậy: \(\frac{23}{5}+\frac{7}{10}< x< \frac{20}{3}\)
= > \(\frac{53}{10}< x< \frac{200}{30}\)
Vậy ta tìm được x = {160 ; 161 ; 162 ; .... ; 198 ; 199}