Answer:
[tex]\large\boxed{(8a^2-6ab+4b^2)-(3a^2+5ab-4b^2)=5a^2-11ab+8b^2}[/tex]
Step-by-step explanation:
[tex](8a^2-6ab+4b^2)-(3a^2+5ab-4b^2)\\\\=8a^2-6ab+4b^2-3a^2-5ab-(-4b^2)\\\\=8a^2-6ab+4b^2-3a^2-5ab+4b^2\qquad\text{combine like terms}\\\\=(8a^2-3a^2)+(-6ab-5ab)+(4b^2+4b^2)\\\\=5a^2-11ab+8b^2[/tex]