Question

ajutoooooooooooooooooooooor

Answer 1

(5-3√2)²+(5+3√2)²=25-30√2+18+25+30√2+18=86∈N
se aplica formulele
(a-b)²=a²-2ab+b²
(a+b)²=a²+2ab+b²

Answer 2

(5-3√2)² + (5+3√2)² =

Aplicam formula (a-b)² = a² +2ab+b² pentru prima paranteza 
          si formula (a+b)²= a²-2ab+b² pentru a doua paranteza

si obtinem :

[ 5² - 2·5·3√2 +(3√2)² ] + [ 5²+2·5·3√2+(3√2)² ] =

Efectuam operatiile :

[ 25-30√2+9·√2² ] + [ 25+30√2+9·√2² ]  =

25-30√2+9·2 + 25+30√2+9·2 =

-30√2 se va reduce cu +30√2 si obtinem :

25+18+25+18 = 50 + 36 = 86

86 este numar real .