Question

simplifique a expressão (2a+b)² - (a-b)²​

Answer 1

$(2a+b)^2-(a-b)^2=\\\\=(4a^2+4ab+b^2)-(a^2-2ab+b^2)=\\\\= (4-1)a^2+[4-(-2)]ab+(1-1)b^2=\\\\= 3a^2+6ab$