Question

rezolvati ecuatia de fradul 2
3xpatrat-2x-5=0

Answer 1

3x² - 2x - 5 = 0
Δ = 4 -4 ·3· ( -5) = 4 + 60 = 64 
x= (2 - 8) / 2· 3 = - 6 /6 = -1
x= ( 2 + 8) / 2· 3= 10 / 6 = 5 /3 
S = { - 1 ; 5 /3 } 
Δ= b² - 4ac  
in ex            a=3  ; b= -2     ; c= - 5 

Answer 2

$\displaystyle 3x^2-2x-5=0 \\ a=3,b=-2,c=-5 \\ \Delta=b^2-4ac=2^2-4 \cdot 3 \cdot (-5)=4+60=64\ \textgreater \ 0 \\ x_1= \frac{2+ \sqrt{64} }{2 \cdot 3} = \frac{2+8}{6} = \frac{10}{6} ^{(2} = \frac{5}{3} \\ \\ x_2= \frac{2- \sqrt{64} }{2 \cdot 3} = \frac{2-8}{6} = \frac{-6}{6} =-1 \\ \\ S=\left\{-1, \frac{5}{3} \right \}$