急 解方程:70%X+(3000-X)*55%=3000*65%
问题描述:
急 解方程:70%X+(3000-X)*55%=3000*65%
答
70%*X+(3000-X)*55%=3000*65%
0.7X+1650-0.55X=1950
0.15X=300
X=300/0.15
X=2000