Question 818171
foil this 2x^2+9* 2x^2+9 and go back to 4x^4+36x^2+81

2x^2*2x^2=4x^4
2x^2*9=18x^2
9*2x^2=18x^2
9*9=81
add them and we have 
4x^4+36x^2+81
convert 
let y=2x^2
y^2+18y+81
we now want factors of 81 which add up to 18
9*9=81 
9+9=18
so now we have 
(y+9) but y=2x^2
so we have 
2x^2+9