Question

x(x-1)-x+15=0 cum se rezolva

Answer 1

x(x-1)-x+15=0
x²-x-x+15=0
x²-2x+15=0
Δ=(-2)²-4×1×15=4-60=-56
Δ<0    ecutia nu admite radacini reale dar admite solutii complexe 
i²=-1
x =(2-√-56)/2=(2-√56i²)/2=(2-2i√14)/2=2(1-i√14)/2=1-i√14
x =(2+√-56)/2=(2+√56i²)/2=(2+2i√14)/2=2(1+i√14)/2=1+i√14