Răspuns:
(1-√2)(1+√2)=1^2-√2^2 = 1-2=-1
(1-√2)^2=1-2√2+2=-1+2√2
(1+√2)^2=1+2√2+2=3+2√2
x=-1+(-1+2√2)+3+2√2
x= 2-1+2√2+2√2
x=1+4√2
