设y1=1/5x+1,y2=（2x+1）/4,当x为何值时,y1,y2互为相反数?

Question

设y1=1/5x+1,y2=（2x+1）/4,当x为何值时,y1,y2互为相反数?

Answer 1

y1,y2互为相反数
所以y1=-y2
所以1/5x+1=-(2x+1)/4
两边乘20
4x+20=-10x-5
14x=-25
x=-25/14