Question

(k-b)ao quadrado + (k-b).(k+b)-(b+2k)ao quadrado

Answer 1

(K-b).(k-b)+(k-b).(k+b)-(b+2k).(b+2k)=
(k²-kb-kb+b²)+k²+kb-kb-b²-(b²+2kb+2kb+4k²)=
k²-2kb+b²+ k²-b²-b²-4kb-4k²=
k²+k²-4k²-2b²+b²-2kb-4kb=
-2k²-b²-6kb=0
∆= b²-4.a.c -> ∆= -1²-4.(-2).(-6)= 25
x=-b+√∆/ 2.a -> x= -(-2)+5/ 2.(-2) -> x=7/-4
x'=-b-√∆/ 2.a -> x'=-(-2)-5/ 2.(-2) -> x'=-3/-4 -> x'= 3/4

Answer 2

(k-b)²+ (k-b).(k+b)-(b+2k)²
(k-b).(k-b)+(k-b).(k+b)-(b+2k).(b+2k)
k²-kb-kb+b² +k²+kb-kb-b²-(b²+2kb+2kb+4k²)
k²-kb-kb+b² +k²+kb-kb-b²-b²-2kb-2kb-4k²
-2k²-6kb-b²

Resposta: -2k²-b²-6kb