Will mark you as brainliest. if your good with polynomials.

To solve/simplify this all you have to do is group like terms (the x^2's with each other, the x's with each other, and the normal numbers, -8)

14x^2-8+5x-6x^2+2x

group the x^2 (add 14x^2 to -6x^2)

8x^2-8+5x+2x

group the x's together (add 5x and 2x together)

8x^2+7x-8

Your answer will be d) 8x^2+7x-8

125% of something is that something multiplied by 1.25. So, multiplying 1,400 by 1.25, we get 1.25(1,400)=1750. Hope this helped!