Question

Descompuneti in factori : x la puterea 2 - 8x+7

Answer 1

x^2-8x+7
S=-8
P=7-> -7
      ->-1
x^2-7x-1x+7
x(x-7)-1(x-7)
(x-1))(x-7)
 PS; ^2= la a 2 a
S= suma
P=produs adica -7 ori -1= 7 si -7 +(-1)=-8 daca suma iti da -8 si produsul 7 inseamna ca e bine

Answer 2

[tex] x^{2} -8x+7=0 [/tex]
Δ=b²-4ac,unde a=1;b=-8;c=7
Δ=64-28=36
$x_{1,2} = \frac{-b+sau- \sqrt{delta} }{2a} = \frac{8+sau-6}{2} \\ x_{1} =7 si x_{2} =1$
 x^{2} -8x+7=0=[tex]a(x- x_{1} )(x- x_{2} )=(x-7)(x-1) [/tex]
sau
Gasim 2 nr care adunate sa faca -8 si inmultite 7.Acestea sunt -1 si-7.
x^{2} -8x+7=0=x²-x-7x+7=x(x-1)-7(x-1)=(x-1)(x-7)