(200+x)(50-2x/10)=10120
(200+x)(50-2x/10)=10120
日期：2022-03-31 12:19:52 人气：1
(200+x)(50-2x/10)=10120
(200+x)(50-x/5)=10120
10000-40x+50x-x*x/5=10120
10x-x*x/5=120
x*x-50x=-600
x*x-50x+625=25
(x-25)²=25
x-25=±5
x=30 or 20
(200+x)(50-x/5)=10120
10000-40x+50x-x*x/5=10120
10x-x*x/5=120
x*x-50x=-600
x*x-50x+625=25
(x-25)²=25
x-25=±5
x=30 or 20