设定价为x元.
{[(2.2-x)/0.1]*2000+5000}*(x-1.5)=4500
{[(2.2-x)/0.1]*4+10}*(x-1.5)=9
{(22-10x)*4+10}*(x-1.5)=9
{(22-10x)*2+5}*(2x-3)=9
(49-20x)*(2x-3)=9
-40x²+158x-147-9=0
20x²-79x+78=0
(x-2)(20x-39)=0
解得x1=2,x2=1.95
设定价为x元.
{[(2.2-x)/0.1]*2000+5000}*(x-1.5)=4500
{[(2.2-x)/0.1]*4+10}*(x-1.5)=9
{(22-10x)*4+10}*(x-1.5)=9
{(22-10x)*2+5}*(2x-3)=9
(49-20x)*(2x-3)=9
-40x²+158x-147-9=0
20x²-79x+78=0
(x-2)(20x-39)=0
解得x1=2,x2=1.95