已知y=2y1+y2,y1与x-2成正比,y2与5x成反比,求y与x的函数关系式?当x=2时,y=9/10;当x=1时,y=1/5

问题描述:

已知y=2y1+y2,y1与x-2成正比,y2与5x成反比,求y与x的函数关系式?
当x=2时,y=9/10;当x=1时,y=1/5

很简单呐,哈哈!y1=k1(x-2)...(1)y2=k2/(5x)...(2)y=2y1+y2=2k1(x-2)+k2/(5x)...(3)当x=2时,y=9/10得9/10=2k1(2-2)+k2/(5*2)即k2=9...(4)当x=1时,y=1/5得1/5=2k1(1-2)+k2/(5*1)所以k1=4/5...(5)总之y=2*4/5(x-2)+9/(5...