1750+70x-50x-2x^2=.=-2(x-5)^2+1800求详细解

问题描述:

1750+70x-50x-2x^2=.=-2(x-5)^2+1800求详细解

1750+70x-50x-2x^2
=1750+20x-2x^2
=-2(x^2-10x)+1750
=-2(x^2-10x+25-25)+1750
=-2(x-5)^2+50+1750
=-2(x-5)^2+1800