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a)2x²-5x=0 si c)5x²+8=0
Va rog mult am nevoie pe mine va rog mult :( Dau coroana""


Răspuns :

2x²-5x=0=>x(2x-5)=0=>x=0 si 2x-5=0=>2x=5=>x=5/2
5x²+8=0=>5x²=-8=>x²=-8/5 care nu se poate =>solutia e multimea vida Ф 
[tex]a)2 x^{2} -5x=0 \ \textless \ =\ \textgreater \ 2 x^{2} =5x \ \textless \ =\ \textgreater \ 2x=5 \ \textless \ =\ \textgreater \ x = \frac{5}{2} =2,5[/tex]

[tex]c)5 x^{2} +8=0 \ \textless \ =\ \textgreater \ 5 x^{2} =-8 \ \textless \ =\ \textgreater \ x^{2} =8:5\ \textless \ =\ \textgreater \ x^{2} =-1,6 [/tex] \ = \ [tex]x= -\sqrt{1,6} [/tex]