What you want to do here is plug 2 in for x. when a question asks you to evaluate a certain equation at a certain number, it's just asking you to plug the value in for your variable. i'm assuming that 12x + 8 is meant to be set over 4 as a fraction.
(12(2) + 8)/4 ... figure out the top first. 12*2 = 24, 24 + 8 = 32.
32/4 = 8, so your correct choice is D.
The absolute change in price was $12−$8=$4. Relative to the original price, it was 412, which is 0.3333 or 33.33%.
The answer was 1,150.0 but as a whole number its 1,150.
The height could be 2 and the width 10 or the height could be 10 and the width could be 2.