(2x²+9x+9)/(x²+xy+3x+3y )
=(2x+3)(x+3) / [ x(x+y)+3(x+y) ]
=(2x+3)(x+3) / [(x+3)(x+y)]
=(2x+3)/(x+y)
代入x,y
(2x+3)=(2*1/2+3)=4
(x+y)=1/2+1/3=5/6
原式=4/(5/6)=24/5=4.8