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Care dintre urmatoarele propozitii sunt adevarate pentru orice numere reale x,y orice numar natural n ?
a) (x+y)²=x²+y²
b) (x+2)²=x²+2x+4
c) (x+y)²=x²-y²
d) (2x+1)²=4x²+4x+1
e) (x-y)²=(y-x)²
f) (4-x²)=16-8x+x²
g) (√3+1)²=4+2√3
h) (√2-√3)²=5-2√6
i) (√5+1)²=6+2√5
j) (3-√2)²=11-6√2
k) (2n+1)²=4n+2n+1+1
l) (3n+1)²=9n+2×3n+1
m) (4n+1)²=4²n+2n+1+1
n) (3n+2n)²=9n+2×6n+4n