Question

\(\frac{x-5}{45}+\frac{x-7}{43}=\frac{x-9}{41}+\frac{x-11}{39}\)

giải giùm em với, tìm msc không được

Answer 1

\(\frac{x-5}{45}-1+\frac{x-7}{43}-1=\frac{x-9}{41}-1+\frac{x-11}{39}-1\)

\(\Leftrightarrow\frac{x-50}{45}+\frac{x-50}{43}=\frac{x-50}{41}+\frac{x-50}{39}\)

\(\Leftrightarrow\left(x-50\right)\left(\frac{1}{45}+\frac{1}{43}-\frac{1}{41}-\frac{1}{39}\right)=0\)

\(\Leftrightarrow x-50=0\) (do \(\frac{1}{45}+\frac{1}{43}-\frac{1}{41}-\frac{1}{39}\ne0\))

\(\Rightarrow x=50\)