{1}18x-1.5x=82.5
x(18-1.5)=82.5
16.5x=82.5
x=5
{2}8.5x-x=38.5
x(8.5-1)=38.5
7.5x=38.5
x=5
(3)0.75x+81.5x=3294
x(0.75+81.5)=3294
82.25x=3294
x≈40