Question

Calcule as Expressões:
a) a(5a-1) + (a+2)²
b) (9y+1)² - (y+9)²

Obrigada a qm responder

Answer 1

$a) a(5a-1)+(a+2)^2= \\ 5a^2-a+a^2+4a+4= \\ \boxed{6a^2+3a+4}$

$b) (9y+1)^2-(y+9)^2 = \\ 81y^2+18y+1-(y^2+18y+81) = \\ 81y^2+18y+1-y^2-18y-81= \\ 80y^2-80 = \\ 80(y^2-1) = \\ \boxed{80(y+1)(y-1)}$