[tex] \green{(a + b)(a - b)= {a}^{2} - {b}^{2}} [/tex]
[tex](5x {}^{2} + 1)(5x {}^{2} - 1) = \\ = 5 {}^{2} (x {}^{2} ) {}^{2} - 1 {}^{2} = \\ = 25x {}^{4} - 1[/tex]
Explicație pas cu pas:
[tex] \bf (5 x^{2}+1) \cdot(5 x^{2} -1) = [/tex]
[tex]\bf (5 x^{2})^{2} - 1^{2} = \red{ \underline{25x^{4} - 1}}[/tex]
