Question

Add
5a2+ 2ab-b2,
-9a2 - ab + 3b2
and 6a2-4ab + 12b²​

Answer 1

Answer: $2a^{2} -3ab+14b^{2}$

Step-by-step explanation:

$5a^2+2ab-b^2-9a^2-ab+3b^2+6a^2-4ab+12b^2\\\\(5a^2-9a^2+6a^2)+(2ab-ab-4ab)+(-b^2+3b^2+12b^2)\\(11a^2-9a^2)+(2ab-5ab)+(-b^2+15b^2)\\=2a^2-3ab+14b^2$