Răspuns:
Explicație pas cu pas:
(2a-b)(2a+b) = [tex](2a)^{2} - b^{2}[/tex] = [tex]4a^{2} - b^{2}[/tex]
(5x+y)(y-5x) = (y+5x)(y-5x) = [tex]y^{2} - (5x)^{2} = y^{2} - 25x^{2}[/tex]
(6a+5b)(6a-5b) = [tex](6a)^{2} - (5b)^{2} = 36a^{2} - 25b^{2}[/tex]
[tex](x-3y)^{2} = x^{2} - 6xy + (3y)^{2} = x^{2} - 6xy + 9y^{2}[/tex]
