2(x+2)^2-11
2x^2+8x-3
1 Move the coefficient of x to the front & write the rest normally
2(x^2+4x-3/2)
2 Divide coefficient of x by 2 squared
2[x^2+4x+(4/2)^2-(4/2^2)-3/2]
3 Put the first terms into ( )^2
2[(x+2)^2-4-3/2]
4 Add the last 2 terms
= 2(x+2)^2-11