\(\dfrac{x-13}{87}+\dfrac{x-27}{73}+\dfrac{x-67}{83}+\dfrac{x-73}{27}=4\)
<=>\(\dfrac{x-13}{87}-1+\dfrac{x-27}{73}-1+\dfrac{x-67}{83}-1+\dfrac{x-73}{27}-1=0\)
<=>\(\dfrac{x-100}{87}+\dfrac{x-100}{73}+\dfrac{x-100}{83}+\dfrac{x-100}{27}=0\)
<=>\(\left(x-100\right)\left(\dfrac{1}{87}+\dfrac{1}{73}+\dfrac{1}{83}+\dfrac{1}{27}\right)=0\)
Do \(\dfrac{1}{87}+\dfrac{1}{73}+\dfrac{1}{83}+\dfrac{1}{27}>0\)
=>x-100=0
<=>x=100
\(\dfrac{x-13}{87}+\dfrac{x-27}{73}+\dfrac{x-67}{83}+\dfrac{x-73}{27}=4\)
\(\Rightarrow\left(\dfrac{x-13}{87}-1\right)+\left(\dfrac{x-27}{73}-1\right)+\left(\dfrac{x-67}{83}-1\right)+\left(\dfrac{x-73}{27}\right)=0\)
\(\Rightarrow\dfrac{x-100}{87}+\dfrac{x-100}{73}+\dfrac{x-100}{83}+\dfrac{x-100}{27}=0\)
\(\Rightarrow\left(x-100\right)\left(\dfrac{1}{87}+\dfrac{1}{73}+\dfrac{1}{83}+\dfrac{1}{27}\right)=0\)
\(\Rightarrow x-100=0\Rightarrow x=100\)