\(\left(x-12,5\right):\frac{3}{4}=\frac{8}{5}\)
\(x-12,5=\frac{8}{5}.\frac{3}{4}\)
\(x-12,5=\frac{6}{5}\)
\(x=\frac{6}{5}+12,5\)
\(x=\frac{137}{10}\)
\(\left(x-\frac{2}{5}\right)\times\frac{5}{11}=\frac{75}{22}\)
\(x-\frac{2}{5}=\frac{75}{22}:\frac{5}{11}\)
\(x-\frac{2}{5}=\frac{15}{2}\)
\(x=\frac{15}{2}+\frac{2}{5}\)
\(x=\frac{79}{10}\)
Bài làm
\(\left(X-12,5\right):\frac{3}{4}=\frac{8}{5}\)
\(\left(X-\frac{25}{2}\right)=\frac{8}{5}x\frac{3}{4}\)
\(X-\frac{25}{2}=\frac{6}{5}\)
\(X=\frac{6}{5}+\frac{25}{2}\)
\(X=\frac{30}{10}+\frac{125}{10}\)
\(X=\frac{155}{10}\)
\(X=\frac{31}{2}\)
~ Câu b) tương tự, chỉ đổi dấu thôi ~
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