已知y1=2x+8,y2=6-2x. (1)当x取何值时,y1=y2; (2)当x取何值时,y1比y2小5.

问题描述:

已知y1=2x+8,y2=6-2x.
(1)当x取何值时,y1=y2
(2)当x取何值时,y1比y2小5.

(1)由题意可列方程2x+8=6-2x,
解得:x=-

1
2

(2)由题意可列方程6-2x-(2x+8)=5,
解得:x=-
7
4