Question

已知a2-ab-6b2=0,求a分之b+b分之a

Answer 1

a2-ab-6b2=0,(a-3b)(a+2b)=0,a=3b或a=-2b,a分之b+b分之a=3分之10或=-2分之5

Answer 2

等式两边都除以a^2
1-b/a-6(b/a)^2=0
得b/a=-1/2或1/3
所以所求=-1/2-2=-2.5
或=1/3+3=3又1/3