Question

Cât este:
x la pătrat+3x+2
x la pătrat+5x+4
x la pătrat+8x+7
Mersi mult oricum

Answer 1

x²+3x+2 = 0

∆ = b²-4ac
∆ = 9-8
∆ = 1.

x1 = -b+√∆/2a
x1 = -3+1/2
x1 = -1.

x2 = -b-√∆/2a
x2 = -3-1/2
x2 = -2.

a(x-x1)(x-x2) = (x+1)(x+2).


x²+5x+4 = 0

∆ = b²-4ac
∆ = 25-16
∆ = 9.

x1 = -b+√∆/2a
x1 = -5+3/2
x1 = -1.

x2 = -b-√∆/2a
x2 = -5-3/2
x2 = -4.

a(x-x1)(x-x2) = (x+1)(x+4).



x²+8x+7 = 0.

∆ = b²-4ac
∆ = 64-28
∆ = 36.

x1 = -b+√∆/2a
x1 = -8+6/2
x1 = -1.

x2 = -b-√∆/2a
x2 = -8-6/2
x2 = -7.

a(x-x1)(x-x2) = (x+1)(x+7).


Little White Lies

Answer 2

1) x²+3x+2
x²+3x+2=0
a=1
b=3
c=2
∆=b²-4ac
∆=3²-4×1×2
∆=9-8
∆=1
x(1,2)=(-b±√∆)/2a
x(1,2)=(-3±√1)/(2×1)
x(1,2)=(-3±1)/2
x(1)=(-3+1)/2
x(1)=-2/2
x(1)=-1
x(2)=(-3-1)/2
x(2)=-4/2
x(2)=-2

2) x²+5x+4
x²+5x+4=0
a=1
b=5
c=4
∆=b²-4ac
∆=5²-4×1×4
∆=25-16
∆=9
x(1,2)=(-b±√∆)/2a
x(1,2)=(-5±√9)/(2×1)
x(1,2)=(-5±3)/2
x(1)=(-5+3)/2
x(1)=-2/2
x(1)=-1
x(2)=(-5-3)/2
x(2)=-8/2
x(2)=-4

3) x²+8x+7
x²+8x+7=0
a=1
b=8
c=7
∆=b²-4ac
∆=8²-4×1×7
∆=64-28
∆=36
x(1,2)=(-b±√∆)/2a
x(1,2)=(-8±√36)/(2×1)
x(1,2)=(-8±6)/2
x(1)=(-8+6)/2
x(1)=-2/2
x(1)=-1
x(2)=(-8-6)/2
x(2)=-14/2
x(2)=-7