Question

ajutor care mă ajută are coroana !

Answer 1

1.
a)
4x²+2x=2x(2x+1)

b)x³-x²=x²(x-1)

c) x²+2x+1=(x+1)²=(x+1)(x+1)

d) x²+6x+5=x²+5x+x+5=x(x+5)+(x+5)=(x+5)(x+1)

e)4x²-25=(2x+5)(2x+5)

2)
a)1999 ×2001=(2000-1)(2000+1)=2000²-1²=4000000-1=3.999.999
b)
398×402=(400-2)(400+2)=400²-2²=160000-4=159.996
3.
x²=9⇒x₁=√9=3  si x₂=-√9=-3

b) x²=16/25  ⇒  x₁=√16/25=4/5     si x₂=-√16/25=-4/5

c) x²=3  ⇒x₁=√3  si x₂=-√3

d) x²=2,25 ⇒x₁=1,5  si x₂=-1,5

e) x²=8  ⇒x₁=√8=2√2  si x₂=-√8=-2√2

Answer 2

$\sqrt{8} =2 \sqrt{2}$
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