Question

разложите на множители кв трехчлен
плииииииииз

Answer 1

$x^2+x-42=(x-6)(x+7) \ x^2+x-42=0 \ D=1+168=169 \ x_1=frac{-1+13}{2}=6 \ x_2=frac{-1-13}{2}=-7$

 

$2x^2+7x-4=(2x-1)(x+4) \ 2x^2+7x-4=0 \ D=49+32=81 \ x_1=frac{-7+9}{4}=0.5 \ x_2=frac{-7-9}{4}=-4$

 

$5x^2-3x-2=(x-1)(5x+2) \ 5x^2-3x-2=0 \ D=9+40=49 \ x_1=frac{3+7}{10}=1 \ x_2=frac{3-7}{10}=-0.4$

 

$3x^2+5x+2=(3x+2)(x+1) \ 3x^2+5x+2=0 \ D=25-24=1 \ x_1=frac{-5+1}{6}=-frac{2}{3} \ x_2=frac{-5-1}{6}=-1$

 

$2x^2-7x+6=(x-2)(2x-3) \ 2x^2-7x+6=0 \ D=49-48=1 \ x_1=frac{7+1}{4}=2 \ x_2=frac{7-1}{4}=1.5$

Answer 2

N 1

X^2 + X - 42 = (X-1)*(X+7)

D = 169

V D = 13

X1 = 1

X2 = - 7

 

 N 2

2X^2 + 7X - 4 = (X - 0.5)*(X + 4)

D = 49 - 4*2*(-4) = 49+32=81

VD = 9

X1 = (-7+9)4 = 24 = 0.5

X2=(-16)4=( - 4)

N 3

 

 

5X^2 - 3X - 2 = (X+0.4)*(X-1) 

D = 49

VD = 7

X1 = 1

X2 = - 0.4

N 4

3X^2 + 5X + 2 = (X+23)*(X+1)

D = 1

V D = 1

X1 = - 46 = - 23

X2 = - 1

N 5

2X^2 - 7X + 6 = (X-2)*(X-1.5)

D = 1

V D = 1

X1 = 2

X2 = 64 = 1.5