2х(в квадрате) -3х-14=0, через дискриминант поиогите пожалуйста! буду благодарна!

2

Ответы и объяснения

2013-03-02T10:49:35+00:00

2х"2-3х-14=0

Д=9+112=121

х1=3+11/4=3.5

х2=3-11/4=-2

 

 

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Лучший Ответ!
2013-03-02T11:20:05+00:00

2x^2-3x-14=o

D=b^2-4ac=(-3)-4*2*(-14)=9+112=121>0, 2 корня

x1= -b+√D = 3+11 =  14 = 7 = 3.5

            2a        2*2         4     2

x2= -b-√D = 3-11 = -8 = -2

          2a          4        4 

или вот так можно(быстрее и проще)

2x^2-3x-14=0

(2x-7)(x+2)=0

2x-7=0 или x+2=0 

2x=7              x=-2

x=3.5