Question

(x+2)(x-2)(x+1)(x-1)+5x²=20

Answer 1

(x+2)(x-2)=x²-4
(x+1)(x-1)=x²-1
portanto,

(x+2)(x-2)(x+1)(x-1)+5x²=20
(x²-4)(x²-1)+5x²=20
x^4-x²-4x²+4+5x²=20
x^4-5x²+5x²=20-4
x^4=16
x=2

Answer 2

Resposta:

(x+2)(x-2)=x²-4

(x+1)(x-1)=x²-1

(x+2)(x-2)(x+1)(x-1)+5x²=20

(x²-4)(x²-1)+5x²=20

x^4-x²-4x²+4+5x²=20

x^4-5x²+5x²=20-4

x^4=16

x=2

Explicação passo-a-passo: