I'm not sure what you mean by the largest solution, but I'll try my best:
First I used foil on the (x+3)(x+3) that gave me:
x^2 +3x +3x +9 -4 =0
I combined like terms and got:
x^2 +6x +5 = 0
Then I used the sum-product method to get what x would equal:
I got (x+3) and (x+2) but the answers were x= -3 and x= -2
so I guess out of the two solutions -2 would be the largest because it's greater than -3
