PT<=> \(\left(\frac{x-17}{33}-1\right)+\left(\frac{x-21}{29}-1\right)+\left(\frac{x}{25}-2\right)=0\)
<=> \(\frac{x-50}{33}+\frac{x-50}{29}+\frac{x-50}{25}=0\)
<=> \(\left(x-50\right)\left(\frac{1}{33}+\frac{1}{29}+\frac{1}{25}\right)=0\)
Mà \(\frac{1}{33}+\frac{1}{29}+\frac{1}{25}\ne0\)
<=> x -50 = 0
<=> x = 50