(For full answer you might have to go to the comments)
Answer: 11x-16y+x^2
Step By Step:
1. Expand
8x+2y+3(x-6y)+x^2
((^ MEANS EXPONENTS OR TO THE POWER OF))
2. Expand
8x+2y+3x−18y+x^2
3. Collect like terms
(8x+3x)+(2y-18y)+x^2
4. Simplify
11x-16y+x^2