规定a*b=a+(a+1)+(a+2)+…+(a+b-1)(ab均为自然数b>a),如果χ﹡10=72,求χ是多少?){3@0S2F8M;b)N+x3n2W
算式:提示:O,@)Z+e9F-D-p){3@0S2F8M;b)N+x3n2W
答:χ是0B+g(u/e6U。){3@0S2F8M;b)N+x3n2W