Răspuns :
A) (x-1)(x+1)=x la puterea a 2-a (notam x^2) -1
x^2-1-x^2-2x=x-10 (se reduc x^2)
-1-2x=x-10 => x=3
B) folosesti relatia (a+b)^3=a^3+b^3+3ab(a+b)
x^2-1-x^2-2x=x-10 (se reduc x^2)
-1-2x=x-10 => x=3
B) folosesti relatia (a+b)^3=a^3+b^3+3ab(a+b)