Question 421440
25x^2 - 40xy + 16y^2

=(5x)^2 - 2*5x*4y + (4y)^2

= (5x-4y)^2


because, we know that (a-b)^2 =a^2 -2ab + b^2


you can also use it....


25x^2 - 40xy + 16y^2

=25x^2 - 20xy -20xy + 16y^2

= 5x(5x-4y)- 4y(5x-4y)

= (5x-4y)(5x-4y)