39x6 + 19x12 + 35x7 + 26x9 = x6(39 + 19x6 + 35x + 26x3)The numerical value of that expression completely depends on the value of 'x',and it changes immediately whenever 'x' changes.
My truck gets about 10 mpg, so I can go 12*10= 120 miles. And my truck gets 19 mpg, so I can go 19x12= 228 miles.
It will fit, but you have to remove the rear ducts for the brakes, this won't do no harm to your car. Ducts are there to help cool the brakes, but no problem at all for everyday driving . Also it will sticks out about an inch or so. A c5 z06 with fender flares and 19x12 rest wheels look very beasty