应该是很简单的,但是我不明白答案为何是4.5
IfX=ab/c,whatistheresultonXofdoublinga,triplingb,andquadrupling
(A)Xismultipliedby1.5
(B)Xismultipliedby3
(C)Xismultipliedby4.5
(D)Xismultipliedby6
(E)Xismultipliedby9
为什么不是A?