2X+4X（20—X）=44怎么做?跪谢!要半小时以内!
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