1.(30%*400+15%*800)/(400+800)
2.1125-500=625
(10%*500+X*625)/1125=20 自己解X
3.20%*50/(50+50)
(20%*50+25)/(50+50+25)
(20%*50+25+20%*125)/(50+50+25+125)
求会浓度的数学高手帮忙解浓度的数学题,急,过程要清楚,今天就要~~~~~~~~
1.(30%*400+15%*800)/(400+800)
2.1125-500=625
(10%*500+X*625)/1125=20 自己解X
3.20%*50/(50+50)
(20%*50+25)/(50+50+25)
(20%*50+25+20%*125)/(50+50+25+125)