Question

3) a)efectuand: (2x-3)²    b) efectuand: 2006²-1006²  c)rezultatul calculului: 2002·1989+2002·2001+2002·400

4) a)descopunand in factori: 5x²+25x  b)decopunand in factori: x²-25x²  c)decopunand in factori:x²+10x+25

5) a) multimea solutiei ecuatiei: x²=49supra 64

     b)media geometrica a nr: (√2-1)²si (√2+1)²

    c)rezolvand in /R ecuatia : √(x-1)²=4 obtinem S={..............}

6)calculati : (x+2)(x-2)-2(x+1)²+3(x-3)²

7)determinati nr reale x si y stiind ca x²+4y²-6x+4y+10=0

8)determinati cea mai mica valoare a expresiei: E=√a²-6a+34  +√b²+14b+58  unde a,b∈ /R 

Answer 1

3C: rezultatul  9583574

Answer 2

4) a)descopunand in factori: 5x²+25x =5x(x+5)
 
b)decopunand in factori: x²-25x² 
(x+5)(x-5)

c)decopunand in factori:x²+10x+25
(x+5)^2
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5) a) multimea solutiei ecuatiei: x²=49supra 64    

x= radical din 49/64
x=7/8

b)media geometrica a nr: (√2-1)²si (√2+1)²   

 media geom=radical din (√2-1)² * (√2+1)²   
=(r2-1)(r2+1)=
2-1=1

c)rezolvand in /R ecuatia : √(x-1)²=4 obtinem S={..............}

√(x-1)²=4/()^2
(x-1)^2=16
x^2-2x+1=16
x^2-2x=15
x^2-2x-15=0
Delta=4+60
delta=64
radical din delta=8
x1=2-8/2=-6/2
x1=-3
x2=2+8/2
x2=10/2
x2=5
====================
6)calculati : (x+2)(x-2)-2(x+1)²+3(x-3)²
x^2-4-2(x^2+2x+1)+3(x^2-6x+9)=
x^2-4-2x^2-4x-2+3x^2-18x+27=
2x^2-22x+21