(√2-√3)^2-(√2-1)(√2+1)+2√6
folosim formula (a-b)^2=a^2-2ab+b^2
2-2√6+3-(√2-1)(√2+1)+2√6
simplifici -2√6 cu +2√6 si faci calculul 2+3
5-(√2-1)(√2+1)
folosim formula (a+b)(a-b)=a^2-b^2
5-(2-1)
5-1=4
