Answer:
[tex]x^{2} +11x-10[/tex]
Step-by-step explanation:
[tex](13x^{2} +9x-4)-(12x^{2} -2x+6)[/tex]
Remove the brackets and multiply the minus sign through all the numbers in the second polynomial
[tex]13x^{2} +9x-4-12x^{2} +2x-6[/tex]
Rearrange in the highest order
[tex]13x^{2} -12x^{2} +9x+2x-4-6[/tex]
Simplify
[tex]x^{2} +11x-10[/tex]