Question

(3ab- 6a²) + ( a²-4ab+2b²) +(5a²-3b²)

Answer 1

$3ab-6a^{2}+a^{2}-4ab+2b^{2}+5a^{2}-3b^{2}\\\\ -6a^{2}+a^{2}+5a^{2}-3b^{2}+2b^{2}+3ab-4ab\\\\ b^{2}-ab\\\\ \Longrightarrow(3ab-6a^{2})+(a^{2}-4ab+2b^{2})+(5a^{2}-3b^{2})=b^{2}-ab$