[tex]\it 25(x+2)^2-16 =5^2(x+2)^2-4^2=[5(x+2)]^2-4^2=\\ \\ \\ =(5x+10)^2-4^2=(5x+10-4)(5x+10+4)=(5x+6)(5x+14)[/tex]
Am folosit formula diferenței pătratelor:
[tex]\it a^2-b^2=(a-b)(a+b)[/tex]
