Question

\(\dfrac{74-x}{26}+\dfrac{75-x}{25}\)

giải phương trình trên

Answer 1

\(\dfrac{74-x}{26}=\dfrac{75-x}{25}\\ \Leftrightarrow\dfrac{74-x}{26}+1=\dfrac{75-x}{25}+1\\ \Leftrightarrow\dfrac{74-x}{26}+\dfrac{26}{26}=\dfrac{75-x}{25}+\dfrac{25}{25}\\ \Leftrightarrow\dfrac{100-x}{26}=\dfrac{100-x}{25}\\ \Leftrightarrow\dfrac{100-x}{26}-\dfrac{100-x}{25}=0\\ \Leftrightarrow\left(100-x\right)\left(\dfrac{1}{26}-\dfrac{1}{25}\right)=0\)

\(Do:\dfrac{1}{26}-\dfrac{1}{25}\ne0\\ \Rightarrow100-x=0\Rightarrow x=100 \)

Vậy S = { 100 }