Răspunsuri

2014-06-20T19:02:34+03:00
 7^{2x} -6 * 7^{x} +5=0
Substitutie:y=7^{x}
 y^{2} -6y+5= y^{2} -5y-y+5=(y-5)(y-1)
 7^{x} =1x=0


Cealalta e cu logaritm,nu stiu daca l-ati facut