a) x(x+2)-(x-3)(x+3)=13=>x*2+2x-(x*2-9)=13=>x*2+2x-x*2+9=13=>2x+9=13=>2x=4=>x=2
b) 4x(x-1)-(2x+5)(2x-5)=1=>4x*2-4x-(4x*2-25)=1=>4x*2-4x-4x*2+25=1=>-4x=-24=>x=6
c) (x-3)(x+4)-2(3x-2)=(x-4)*2=>x*2+4x-3x-12-6x+4=x*2-8x+16=>x*2-5x-8=x*2-8x+16=>x*2-x*2-5x+8x=8+16=>3x=24=>x=8
d) nu vad ce scrie dupa =
