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Descompuneti in factori:
a)64x^2-1
b)7x^4-9x^3-7x^2-9x


Răspuns :

a) (8x-1) (8x+1)
b) x³(7x-9) - x(7x-9) = (7x-9)(x³-x) = (7x-9) *x* (x²-1)=
x(7x-9) (x-1)(x+1)
a)64x^2-1 =(8x+1)(8x-1)
b)7x^4-9x^3-7x^2-9x =7x
4-7x^2-9x^3-9x=7x^2(x^2-1)-9x(x^2-1)=(x^2-1)(7x^2-9x)=
=x(x+1)(x-1)(7x-9)