5x-3x(20-x)=68这道题怎么解?写具体点.
问题描述:
5x-3x(20-x)=68这道题怎么解?写具体点.
答
5x-60x+3x^2=68
3x^2-55x-68=0
x=〔55+〔-〕根号下3229〕/6