Algebra question on gre: $21+x^2 +(x+1)+16+22+17+x = 100$%

Question

$21+x^2 +(x+1)+16+22+17+x = 100$%

The solution guide gives me $x^2 + 2x + 76 = 100$

Then $x^2+2x-24=0$

I just don't get where $x+1$ went..

I keep getting $x^2+2x+77=100$ what am I doing wrong somebody help me]1