Question

  ; 1)Rezolvati in R ecuatia x la puterea 2 - 7x =8

Answer 1

x^ 2 - 7x =8 
x^2-7x-8=0

Delta=b^2-4ac
delta=49-4*1*-8
elta=49+32
delta=81

x1=-b- radical delta/2a
x1=7-9/2
x1=-2/2
x1=-1

x2=-b+ radical delta/2a
x2=7+9/2
x2=16/2
x2=8.

Deci solutiile tale sunt x1=-1 si x2=8

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Faci descompunerea polinomului si vei avea 
(x+1)(x-8)=0
x+1=0
x=-1
x-8=0
x=8