Answer:
[tex]8x^{2}-x-8[/tex]
Step-by-step explanation:
[tex]6x^{2} + 3x-9 - (-2x^{2} +4x-1)\\[/tex]
then multiply the -1 from this part [tex]-1 (-2x^{2} +4x-1)\\[/tex] = [tex]2x^{2} -4x+1[/tex]
next,[tex]6x^{2} +3x-9+2x^{2} -4x+1[/tex] , and COLLECT LIKE TERMS
= [tex]6x^{2} +2x^{2} +3x-4x-9+1[/tex]
= [tex]8x^{2} -x-8[/tex]