设进价x,定价y,则
0.9y-x=215; 0.8y-x=-125
解得:x=2845,y=3400
进价2845元,定价3400元
楼主的回答是错的!!正确的应该是 (215+125)÷(20%-10%)=3400元(得出定价)
3400×(1-10%)-215=2845元(得出进价)
设定价X元
X-10%X-210=X-20%X+125
0.2X-0.1X=210+125
0.1X=335
X=3350
进价=3350-3350*10%-210=2805元
1.先求定价:(215+125)/(20%-10%)
=340/0.1
=3400
2.进价:3400x(1-10%)-215
=3400x0.9-215
=3060-215=2845