Question

1) Multimea solutiilor ecuatiei (2x +5 ) la puterea a doua =169 este S ={..}. 2). Valorile reale ale lui x pentru care x la a doua =(√2 -5 ) la puterea a doua sunt x 1 = .....,x 2=...

Answer 1

x²-169=0
x²-13²=0
(x-13) (x+13)=0

x1,2=+/-13
S={-13;13}



Fie √2-5=b
atunci
x²=(√2-5)²= b²
as simple as that!!
x1=b=√2-5
x2=-b=-√2+5