2x² - 7x + 5 = 0 → ec. de gr. II.
Folosim formulele: [tex]delta=b^2-4ac\\
x_1,x_2= \frac{-b(+~sau~-) \sqrt{delta} }{2a} \\
unde~a=2,b=-7,c=5[/tex]
Rezolvare: [tex]delta=(-7)^2-4*2*5\\
delta=49-40\\
delta=9\\\\
x_1= \frac{-(-7)+ \sqrt{9} }{2*2} =\ \textgreater \ x_1= \frac{7+3}{4} =\ \textgreater \ x_1= \frac{10}{4} (simplificam)=\ \textgreater \ x_1= \frac{5}{2} \\\\
x_2= \frac{-(-7)- \sqrt{9} }{2*2} =\ \textgreater \ x_2= \frac{7-3}{4} =\ \textgreater \ x_2= \frac{4}{4} =\ \textgreater \ x_2=1[/tex]
Scriem solutiile: {1 ; 5/2}
