Output simpler version of symbolic polynomial expression

When I run some MATLAB code, I get a symbolic expression that looks like this:

a*x^2 + 2*a*x*y + b + a*y^2

Looking at it, I know I can rewrite this as

a*(x + y)^2 + b

How do I get MATLAB to output the expression as the latter? Is there even a function to do so?

Answer 1

[madhan ravi]

 syms x y a b 
 z = a*x^2 + 2*a*x*y + b + a*y^2;
 simplify(collect(z, a), 'Steps', 50)