<PRE><B>Question 224534</B>
Assuming that you want to factor this, the first step is to take out the common factor of y^2:


9y^4+42y^3+49y^2
y^2(9y^2+42y+49)


What remains is actually a perfect square trinomial.  The First times First is 3y*3y.
y^2(3y____)(3y_____)


The Last times Last is 7*7.
y^2(3y+7)(3y+7)

y^2(3y+7)^2


R^2</PRE>