25 a² + 20 ab + 4 b²
for formula [tex]a^x+bx^ky^k+cy ^{2k } [/tex] find u,v such that: u.v = a
and u+v = b then group according to [tex](ax ^{2k} +ux^ky^k)+(vx^ky^k+cy ^{2k} )[/tex]
= [tex](25a^2+10ab)+(10ab+4b^2)[/tex]
factor out 5a from : [tex]25a^2+10ab : 5a(2b+5a)[/tex]
factor out 2b from : [tex]10ab+4b^2: 2b(2b+5a)[/tex]
= [tex]5a(2b+5a) + 2b(2b+5a)[/tex]
factor out : [tex](5a+2b)[/tex]
= [tex](5a+2b)(5a+2b)[/tex]
Refine:
[tex](2b+5a)^2[/tex]
hope this helps!.
