Tìm x biết \[\frac{{\left( {1,16 - x} \right).5,25}}{{\left( {10\frac{5}{9} - 7\frac{1}{4}} \right).2\frac{2}}} = 75\% \]

Trả lời:

\[\frac{{\left( {1,16 - x} \right).5,25}}{{\left( {10\frac{5}{9} - 7\frac{1}{4}} \right).2\frac{2}}} = 75\% \]

\[\frac{{\left( {\frac - x} \right).\frac}}{{\left( {\frac{9} - \frac{4}} \right).\frac}} = \frac\]

\[\frac{{\left( {\frac - x} \right).\frac{4}}}{{\frac.\frac}} = \frac{3}{4}\]

\[\frac{{\left( {\frac - x} \right).\frac{4}}}{7} = \frac{3}{4}\]

\[\left( {\frac - x} \right).\frac{4}.4 = 7.3\]

\[\left( {\frac - x} \right).21 = 21\]

\[\frac - x = 21:21\]

\[\frac - x = 1\]

\[x = \frac - 1\]

\[x = \frac{4}\]

Đáp án cần chọn là: C