Question

tìm x 

(X-12,5) : 3/4 = 8/5

(X-2/5) x5/11=75/22

Answer 1

\(\left(x-12,5\right):\frac{3}{4}=\frac{8}{5}\)

\(x-12,5=\frac{8}{5}.\frac{3}{4}\)

\(x-12,5=\frac{6}{5}\)

\(x=\frac{6}{5}+12,5\)

\(x=\frac{137}{10}\)

Answer 2

\(\left(x-\frac{2}{5}\right)\times\frac{5}{11}=\frac{75}{22}\)

\(x-\frac{2}{5}=\frac{75}{22}:\frac{5}{11}\)

\(x-\frac{2}{5}=\frac{15}{2}\)

\(x=\frac{15}{2}+\frac{2}{5}\)

\(x=\frac{79}{10}\)

Answer 3

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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