求初一数学题目答:0.6x+1.1y<=70 0.9x+0.4y<=52有上述三式得36<=x<=40所以x=36,37,38,39,40所以能完成任务x=36,y=44;x=37,y=43;x=38,y=42;x=39,y=41;x=40,y=40;解:设有x辆汽车,y顿货物。则有4x+10=y 7x-7<y<7x有上述两式得10/3<=x<=17/3所以x=4,5所以有四辆或五辆汽车。解:设M时装x套...
已知圆C:X^2+Y^2-4X-6Y-3=0,点A(2,-1),B为圆C上动点,0为坐标原点.动点P...答:向量OP=(X,Y),向量OA=(2,-1),向量OB=(X1,Y1)故有:(x,y)=1/2(2,-1)+(x1,y1)=(1+x1,y1-1/2)即有x=1+x1,y=y1-1/2 即有x1=x-1,y1=y+1/2 而圆C是:(x-2)^2+(y-3)^2=16 故有:(x1-2)^2+(y1-3)^2=16 所以,P的方程是:(x-3)^2+(y-5/...