Question

Sobre produtos notaveis
A) a(5a-1) - (a+2)²

B) (2x+3)² - x(x-4)

C) (y-3)(y+2) - (y+1)²

D) (9y+1)² - (y+9)²

E) (2a+3b)² - 4a(a+3b)

F) (1+5a)² + 25(1-a²)

Answer 1

A) $a(5a-1)-(a+2)^2=5a^2-a-a^2-4a-4=4a^2-5a-4$

B)$(2x+3)^2-x(x-4)=4x^2+12x+9-x^2+4x=3x^3+16x+9$

C)$(y-3)(y+2) - (y+1)^2=y^2+2y-3y-6-y^2-y-1=-2y-7$

D)$(9y+1)^2 - (y+9)^2=81y^2+18y+1-y^2-18y-81=80y^2-80$

E)$(2a+3b)^2 - 4a(a+3b)=4a^2+12ab+9b^2-4a^2-12ab=9b^2$

F)$(1+5a)^2 + 25(1-a^2)=25a^2+10a+1+25-25a^2=10a+26$