Question

rezolvati si descompuneti in produs de factori ecuatia x la a doua -2x-15=0

Answer 1

Salut,

x²-2x-15 = 0.

a = 1
b = -2
c = -15

∆ = b²-4ac
∆ = (-2)²-4•(-15)
∆ = 4+60
∆ = 64.

x1 = (-b-√∆)/2a
x1 = (2-8)/2
x1 = -6/2
x1 = -3.

x2 = (-b+√∆)/2a
x2 = (2+8)/2
x2 = 10/2
x2 = 5.

a(x-x1)(x-x2) = (x+3)(x-5).

Succes!

Answer 2

x^2- 2x - 15 = 0 
d. = 4 + 60 = 64 
x1 = 2+8/2 = 10/2 = 5 
x2 = 2-8/2 = - 6/2 = -3 

s = { -3; 5}