\(\frac{x-20}{x-10}=\frac{x+40}{x+70}\)
\(\Leftrightarrow\left(x-20\right)\left(x+70\right)=\left(x-10\right)\left(x+40\right)\)
\(\Leftrightarrow x^2+70x-20x-140=x^2+40x-10x-140\)
\(\Leftrightarrow50x=30x\)
\(\Leftrightarrow50x-30x=0\)
\(\Leftrightarrow20x=0\)
\(\Leftrightarrow x=0\)
Chết , sửa chút !!! Nhân ngu wá
\(\frac{x-20}{x-10}=\frac{x+40}{x+70}\)
\(\Leftrightarrow\left(x-20\right)\left(x+70\right)=\left(x-10\right)\left(x+40\right)\)
\(\Leftrightarrow x^2+70x-20x-140=x^2+40x-10x-400\)
\(\Leftrightarrow20x+260=0\)
\(\Leftrightarrow x=-13\)
Incursion_03 :>
\(\frac{x-20}{x-10}=\frac{x+40}{x+70}\)
\(\Rightarrow\left(x-20\right).\left(x+70\right)=\left(x-10\right).\left(x+40\right)\)
\(\Rightarrow x^2+50x-1400=x^2+30-400\)
\(\Rightarrow20x=1000\Rightarrow x=50\)
Boul đẹp trai_tán gái đổ 100% làm đúng rồi ... Iam sorry . Nhân đi nhân lại vx nhầm T_T
