Exercitiul 8 va rog dau coroana!!!

a)
[tex] {x}^{2} + 2xy + {y}^{2} = {(x + y)}^{2} [/tex]
b)
[tex] {x}^{2} + {y}^{2} + 2xy = {(x + y)}^{2} [/tex]
c)
[tex]4 {x}^{2} - 4x + 1 = {(2x - 1)}^{2} [/tex]
d)
[tex]9{x}^{2} + 1 + 6x = {(3x + 1)}^{2} [/tex]