\(\frac{x-1}{42}+\frac{2x-1}{83}+\frac{3x-1}{124}=-3\)
\(< =>\frac{10292.\left(x-1\right)}{432264}+\frac{5208.\left(2x-1\right)}{432264}+\frac{3486.\left(3x-1\right)}{432264}=\frac{-3.432264}{432264}\)
\(< =>10292.\left(x-1\right)+5208.\left(2x-1\right)+3486.\left(3x-1\right)=-1296792\)
\(< =>10292x-10292+10416x-5208+10458x-3486=-1296792\)
\(< =>\left(10292+10416+10458\right)x=-1296792+3486+5208+10292\)
\(< =>31166x=-1277806\)
\(< =>x=\frac{-1277806}{31166}\)
\(< =>x=-41\)
\(\Leftrightarrow\frac{5146x-5146+5208x-2604+5229x-1743}{216132}=-3\)
\(\Leftrightarrow\frac{15583x-9493}{216132}=-3\)
\(\Leftrightarrow15583x=-638903\)
\(\Leftrightarrow x=-41\)
Cách nhanh hơn bạn:v
\(\frac{x-1}{42}+\frac{2x-1}{83}+\frac{3x-1}{124}=-3\)
\(\Rightarrow\frac{x-1}{42}+1+\frac{2x-1}{83}+1+\frac{3x-1}{124}+1=0\)
\(\Rightarrow\frac{x+41}{42}+\frac{2x+82}{83}+\frac{3x+123}{124}=0\)
\(\Rightarrow\frac{x+41}{42}+\frac{2\left(x+41\right)}{83}+\frac{3\left(x+41\right)}{124}=0\)
\(\Rightarrow\left(x+41\right)\left(\frac{1}{42}+\frac{2}{83}+\frac{3}{124}\right)=0\Leftrightarrow x=-41\)
