Question

若不论x取任何值时,等式ax-b-4x=3永远成立,则1/2ab的值是多少

Answer 1

ax-b-4x=3

取x=0,ax0-b-4x0=3,b=-3

取x=1,ax1-(-3)-4x1=3,a=4

1/2ab=1/2x4x(-3)=-1/24