1)3x^2-7x+4=0
(3x−4)(x−1)=0 => 3x-4=0 => x=4/3 și x-1=0 => x=1
3) x+2y=8
2x-y=1 /*2
-----------------------(+)
5x=10 => x=2
x+2y=8 => 2+2y=8 => 2y=6 => y=3
2) (2-5x)/(25-x^2) - 2x/(x+3)= -1
25-x^2=5-x^2
(-5x+2)/(x-5)(x+5)-2x/(x+3)=-1 Aducem la acelasi numitor si facem calculele
2x^3−5x^2−63x+6=x^3+3x^2−25x−75
x^3−8x^2−38x+81=0