解题时,有时只要再坚持一下,想得再全面些,迎接你的,或许就是成功.一天晚上我写作业时,碰到了下面这道题目.要使关于x、y的多项式mx~2+2nxy-x+x~2-2xy+y化简后不含二次项,则3m-2n的值为____.这道题目中的m、n都是待定的,因此考虑求出它们.而“化简后不含二次项”说明所有二次项的和等于0,因此要先找二次项.mx~2和x~2是一组可以合并的二次项,根据题意可列出m+1=0,解得m=-1.可是,问题来了!找到这一组后,我停下 Solving problems, sometimes just insist on, want to be more comprehensive, to meet you, or may be successful. One night I was homework, encountered the following problem. To make the polynomial on x, y mx ~ 2 + Since 2nxy-x + x ~ 2-2xy + y does not contain quadratic terms after simplification, the value of 3m-2n is ____. Since m and n in this subject are to be determined, “Simplification does not contain quadratic term ” indicates that all quadratic sum is equal to 0, so to find the second term .mx ~ 2 and x ~ 2 is a set of merged quadratic terms, according to the title May list m + 1 = 0, solve m = -1 However, the problem came! I found this group, I stopped