Question

向量计算 1/3(a+2b)+1/4(3a-2b)-1/2(a-b)

Answer 1

和初中里的合并多项式一模一样，只不过上面加一个向量符号
1/3(a+2b)+1/4(3a-2b)-1/2(a-b)
=a/3+2b/3+3a/4-b/2-a/2+b/2
=7a/12+2b/3

Answer 2

1/3(a+2b)+1/4(3a-2b)-1/2(a-b)

=1/3a＋3/4a-1/2a＋2/3b-1/2b＋1/2b
=7/12a＋2/3b

追问

若2/3(4a-3x)+3(5x-4b)=0,其中ab为向量,求向量x

追答

2/3(4a-3x)+3(5x-4b)=0
8/3a-2x＋15x-12b=0
13x=-8/3a＋12b
x=-8/39a＋12/13b