y=(3+x)(1-2x)化简成y=a(x-h)²+k的形式

分类: 作业答案 • 2022-01-04 11:52:35

问题描述：

答

乘出来
y=-2x²-5x+3
=-2(x²+5x/2)+3
=-2(x²+5x/2+25/16-25/16)+3
=-2(x²+5x/2+25/16)+25/8+3
=-2(x+5/4)²+49/8

答

y=(3+x)(1-2x)
=3-6x+x-2x²
=-2x²-5x+3
=-2(x²+5/2*x)+3
=-2[x²+2*(5/4)*x+(5/4)²-(5/4)²]+3
=-2(x+5/4)²+25/8+3
=-2(x+5/4)²+49/8