Answer:
[tex]\huge\boxed{\sf (7y+3)(7y+3)}[/tex]
Step-by-step explanation:
[tex]\sf = 49y^2+42y+9\\\\=(7y)^2+2(7y)(3)+(3)^2\\\\Using \ Formula \ a^2+2ab+b^2 = (a+b)^2\\\\= (7y+3)^2\\\\= (7y+3)(7y+3)\\\\\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807
