[tex]a=x- \frac{10}{100} *x=x- \frac{x}{10} \\ \\
b=a- \frac{20}{100}*a=a- \frac{2a}{10} \\ \\
b= Pret Final=150 \\ \\
=> 150 = a- \frac{2a}{10}=x- \frac{x}{10}-\frac{2*(x-\frac{x}{10})}{10} \\ \\
=> 150= \frac{10x-x-2x+ \frac{2x}{10}}{10} \\ \\
=> 1500 = \frac{100x-10x-20x+2x}{10} \\ \\
=> 15000 = 72x \\ \\
=> x= \frac{15000}{72} = 208,(3)[/tex]
Acum faci verificarea :D
208,(3)-10%=187,5
187,5-20%=150
:D
