若a≠b,数列a,x1,x2,b和数列a,y1,y2,y3,b都是等差数列,则 x2−x1y2−y1=( ) A.23 B.34 C.1 D.43
问题描述:
若a≠b,数列a,x1,x2,b和数列a,y1,y2,y3,b都是等差数列,则
=( )
x2−x1
y2−y1
A.
2 3
B.
3 4
C. 1
D.
4 3
答
∵a、x1、x2、b成等差数列
∴x2-x1=
(b-a)1 3
∵a,y1,y2,y3,b都是等差数列,
∴y2-y1=
(b-a)1 4
∴
=
x2−x1
y2−y1
.4 3
故选:D.