\(\dfrac{15-x}{7}=\dfrac{x+7}{4}\\ \Leftrightarrow4\left(15-x\right)=7\left(x+7\right)\\ \Leftrightarrow11x=11\\ \Leftrightarrow x=1\)
Vậy x=1
\(60-4x=7x+49\)
\(\Leftrightarrow60-49=4x+7x\)
\(\Leftrightarrow11=11x\)
\(\Rightarrow x=1\)
Ta có: \(\dfrac{15-x}{7}=\dfrac{x+7}{4}\)
\(\Leftrightarrow60-4x=7x+49\)
\(\Leftrightarrow-4x-7x=49-60\)
\(\Leftrightarrow x=1\)
\(\dfrac{15-x}{7}=\dfrac{x+7}{4}\)
\(\Leftrightarrow4\left(15-x\right)=7\left(x+7\right)\)
\(\Leftrightarrow60-4x=7x+49\)
\(\Leftrightarrow7x+4x=60-49\)
\(\Leftrightarrow11x=11\)
\(\Leftrightarrow x=\dfrac{11}{11}=1\) (Thỏa mãn)
Vậy x = 1
