Răspunsuri

2014-09-20T19:16:56+03:00
 x^{2} -3x=4 => x^{2} -3x-4=0


Calculam discriminantul: 
Δ= (-3)^{2} -4*1*(-4)=25.
Δ>0=> Avem 2 solutii reale distincte:
x1= \frac{-b+ \sqrt{delta} }{2a} , x2= \frac{-b- \sqrt{delta} }{2a} =>
x1= \frac{3+5}{2} =4, x2= \frac{3-5}{2} =-1