exercitiul 7 si 8 va rogg urgentt

Exercitiul 7 Si 8 Va Rogg Urgentt class=

Răspuns :

7
a)  =  x^2 + 4x + 4   (fals ) 
b) = 4x^2 + 12x + 9 (fals)
c) = adevarat
d) = 9x^2 + 6x + 1 (fals) 
e) = adevarat
f) = 3x^2  - 2x√6 + 2 (fals) 
g) = adevarat 
h) = 3 - 2√3 + 1 = 4 -2√3 (adevarat) 

8) 
a) = x^2 - 25 (fals )
b) = 4x^2 - 1 (fals) 
c) = adevarat 
d) = adevarat 
e) = 2- x^2 (fals) 
f) = adevarat 
7) a) (x+2)^2 = x^2 + 4
        x^2+4x+4 = x^2 + 4 FALS
   b) (2x+3)^2 = 4x^2+9
       4x^2 + 12x + 9 = 4x^2 + 9 FALS
   c) (3x+1)^2 = 9x^2 + 6x + 1
       9x^2 + 6x + 1 = 9x^2 + 6x+ 1  ADEVARAT
   d) (3x+1)^2 = 3x^2 + 6x+ 1 
        9x^2 + 6x + 1 = 3x^2 + 6x + 1 FALS
   e) (rad 2 *x-1)^2 = 2x^2 - 2 rad 2 *x +1
       2x^2 - 2 rad 2 *x + 1 =  2x^2 - 2 rad 2 * x+ 1 ADEVARAT
   f) (rad 3 * x - rad 2)^2 = 3x^2 - 2
       3x^2 - 2 rad 6 *x + 2 = 3x^2 -2 FALS
   g) (1/2 * x - 2)^2 = 1/4 *x^2 -2x + 4
       1/4 * x^2 -2x + 4 = 1/4 * x^2 - 2x + 4 ADEVARAT
   h) (rad 3 - 1)^2 = 4 - 2 rad 3
       3 - 2rad 3 + 1 = 4 - 2 rad 3
       4 - 2 rad 3 = 4 - 2 rad 3 ADEVARAT

8) a) (x-5)(x+5) = x^2 - 5
        x^2 - 25 = x^2 - 5 FALS
    b) (2x-1)(2x+1) = 2x^2 - 1
        4x^2 - 1 = 2x^2 - 1 FALS
    c) (3-x)(3+x) = 9 - x^2
        9 - x^2 = 9 - x^2 ADEVARAT
    d) (1+3x)(1-3x) = 1 - 9x^2
        1 - 9x^2 = 1 - 9x^2 ADEVARAT
    e) (rad 2 - x)(x + rad 2) = x^2 - 2
        (rad 2 - x)(rad 2 + x) = x^2 - 2
        2 - x^2 = x^2 - 2 FALS
    f) (rad 3 + x)(x - rad 3) = x^2 - 3
       ( x+  rad 3)(x - rad 3) = x^2 - 3
       x^2 - 3 = x^2 - 3 ADEVARAT