∵(9a+8)²+|8a+9b|=0
∴9a+8=0 8a+9b=0
a=-8/9
b=1
∴a²+ab+b²=a²+2ab+b²-ab=(a+b)²-ab=(-8/9+1)²-(-8/9)*1=1/81+8/9=1/81+72/81=73/81