2X+4X(20—X)=44怎么做?
问题描述:
2X+4X(20—X)=44怎么做?
跪谢!要半小时以内!
答
2x+80x-4x^2=44
82x-4x^2=44
41x-2x^2=22
2x^2-41x+22=0