Question

find using suitable identity. (2x-3y)²

Answer 1

a
$(x - y) {}^{2} = x { }^{2} - 2xy + y {}^{2}$
so
$= (2x) {}^{2} - 2(2x)(3y) + (3y) {}^{2}$

Answer 2

for this u should use the identity (a-b)^2 , that is a^2 - 2 ab + b^2 
               given (2x-3y)^2 
                         (2x)^2 - 2(2x)(3y) + (3y)^2
                          4x^2 - 12xy + 9y^2 

              hope this helps ...