Step 1: Expand the square of the binomial (3x+y)^2= 8(9x^2 + 6xy + y^2) - 12x(6x + 4y)= 72x^2 + 48xy + 8y^2 - 72x^2 - 48xy= 8y^2
Therefore, the simplified expression is 8y^2
Step 1: Expand the square of the binomial (3x+y)^2
= 8(9x^2 + 6xy + y^2) - 12x(6x + 4y)
= 72x^2 + 48xy + 8y^2 - 72x^2 - 48xy
= 8y^2
Therefore, the simplified expression is 8y^2