Use the distributive property. For the first set of parenthesis, multiply everything inside by 8. This gets you to 8x-8.
Next set: Everything inside by 3x: 12x+3x^2.
Next set: Everything inside by 6: 6x+12.
Put it all together: 8x-8-12x+3x^2+6x+12-3.
Combine like terms: 2x+1+3x^2
