Question

已知b分之a=2,求a方+ab+6a方分之a方-ab+3b方的值

Answer 1

a/b=2

分式分子分母同除以b²

(a²-ab+3b²)/(a²+ab+6b²)

=[(a/b)²-(a/b)+3]/[(a/b)²+(a/b)+6]

=(2²-2+3)/(2²+2+6)

=5/12