Ответы и объяснения

2014-03-05T05:12:21+00:00
1)х^2+4x-12=0
D=b^2+4ac
D=16-4*1-(12)= \sqrt{64} =8
x1= \frac{-b+ \sqrt{D} }{2a} = \frac{-4+8}{2*1} = \frac{-4}{2} 2
x2= \frac{-4-8}{2*1} = \frac12}{2} =6
2)3x^2+8x-3=0
D=64-4*3*(-3)= \sqrt{100} =10
x1= \frac{-8+10}{2*3} = \frac{-2}{6}= \frac{1}{3}  
x2= \frac{-8-10}{2*3} = \frac{18}{2} =9