Question

Mă puteți ajuta cu rezolvarea primelor doua puncte, a si b
Am nevoie urgenta !!!!

Answer 1

a) notam lg(x)=y
atunci: y*y+4y+3=0 => y(y+3) + (y+3)=0 => (y+3)(y+1)=0
=> y=-3 sau y=-1
=> lgx=-3 => x=1/1000
=>lgx=-1 => x=1/10
b)
notam lg(x)=y
atunci: y*y/6+5*y/12 -1=0 => calculam delta= 121/144 =>
y1=(-(5/12)+(11/12))*3=3/2 => lg x=3/2 => x=rad(1000) (rad inseamna radical de ordin doi)
y2=(-(5/12)-(11/12))*3=-4 => lg x=-4 => x=1/10000