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/(5x)
=8x/5+9/(5x)-16/5
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/(5x)
=8x/5+9/(5x)-16/5