Question

E(x) = x³ + (x+1)² +2(x-3) (x+3) +17

Answer 1

E(x) = x³ + (x+1)² +2(x-3) (x+3) +17
(a+b)^2=a^2+2ab+b^2
(a+b)(a-b)=a^2-b^2

E(x) = x^3 + (x^2+2x+1) + 2(x^2-9) + 17
E(x) = x^3 + x^2+2x+1 + 2x^2-18 + 17
E(x) = x^3 + 3x^2 + 2x

Asta e forma cea mai simpla a ecuatiei. Daca vrei sa aflii cat e x, atunci:

x^3 + 3x^2 + 2x = x(x+1)(x+2)=0 => x=0; x=-1; x=-2