若三點A(2,2),B(a,0),C(0,b)(ab≠0)共線,則1a+1b的值等於______

若三點A(2,2),B(a,0),C(0,b)(ab≠0)共線,則1a+1b的值等於______

AB=(a-2,-2),AC=(-2,b-2),依題意知AB‖AC,有(a-2)•(b-2)-4=0即ab-2a-2b=0所以1a+1b=12故答案為12