Georgianageo181id
a fost răspuns

Calculati, folosind formulele de calcul prescurtat:
a)   (x+2)(x-2)+(x+4)²-2x=?
b)   (2-x)²-(x+3)(x-3)-x(x-1)=?
c)   (x+5)²-2(x-5)(x+5)+x²=?
d)   (6-x)²-3(x+2)-5(x+1)=?
As vrea rezolvarile complete, va rog.

Răspuns :

Miky93id
a)x²-4+x²+8x+16-2x= 2x²+4x+12 =2(x²+2x+3)

b)4-4x+x²-x²+3-x²+x= -2x² +x² -3x +4+3= -x²-3x+7

c)x²+10x+25-2(x²-25)+x²= x²+10x+25 -2x²+50+x²=  2x²-2x²+10x+75= 10x+75= 5(2x+15)

d)36-12x+x²-3x-6-5x-5= x²-20x + 36-11=  x²-20x+25
Tstefanid
a)
(x + 2)(x - 2) + (x + 4)² - 2x =
=x² - 4 + x² + 8x + 16 -2x =
2x² - 6x + 12 

b)
(2-x)²-(x+3)(x-3)-x(x-1)=
= 4 - 4x + x² + x² - 9 - x² + x =
x² - 3x -5

c)
(x+5)²-2(x-5)(x+5)+x²=
= x² + 10x + 25 - 2x² + 50 + x²
= 10x +75

d)
(6-x)²-3(x+2)-5(x+1)=
= 36 - 12x + x² - 3x - 6 - 5x - 5 =
x² - 20x + 25


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