Răspuns :
[tex]a) {x}^{2} - 4xy + 4 {y}^{2} = {(x - 2y)}^{2} [/tex]
[tex]d)25 {a}^{2} - 20a + 4 = {(5a - 2)}^{2} [/tex]
[tex]g) {a}^{2} - 18ac + 81 {c}^{2} = {(a - 9c)}^{2} [/tex]
a) x^2-4xy+4y^2=(x-2y) ^2
d) 25a^2-20a+4=(5a-2)^2
g)a^2-18ac+81c^2=(a-9c)^2
d) 25a^2-20a+4=(5a-2)^2
g)a^2-18ac+81c^2=(a-9c)^2