1
lim(2x²+15x+25)/(x²+15x+50)=(50+75+25)/(25+75+50)=150/150=1
x→5
2
lim(2x²+15x+25)/(x²+15x+50)=(50-75+25)/(25-75+50)=0/0
x→-5
lim(2x²+15x+25)/(x²+15x+50)=lim(2x+5)(x+5)/(x+10)(x+5)=lim(2x+5)/(x+10)=
x→-5 x→-5 x→-5
=(-10+5)(-5+10)=-1
3)lim(2x²+15x+25)/(x²+15x+50)=∞/∞
x→∞
lim(2x²+15x+25)/(x²+15x+50)=limx²(2+15/x+25/x²)/x²(1+15/x+50/x²)=
x→∞ x→∞
=lim(2+15/x+25/x²)/(1+15/x+50/x²)=(2+0+0)/(1+0+0)=2
x→∞