Respuesta :
easily done
the fastest way is to recognize the differnce of 2 perfec squares
(a-b)(a+b)=a²-b²
sp
o
(3x-1)(3x+1)=(3x)²-(1)²=9x²-1
the fastest way is to recognize the differnce of 2 perfec squares
(a-b)(a+b)=a²-b²
sp
o
(3x-1)(3x+1)=(3x)²-(1)²=9x²-1