Descompuneti in factori primi:

1) (x^2+3)^2-4x^2=

2) (5x+1)^2-4x^2=

3) (2-3x)^2-9x^4=

4) 25-(x-3)^2=

5) (4-7x^2)-36=

Va rog ajutati-ma, dau coroană!!​