Contact us
Choose a category below so we can get back to you as quickly as possible.
a1=s1=m*3+1=3m+1 a1+a2=s2=m*3^2+1 3m+1+a2=9m+1 a2=6m a3=s3-s2=m*3^3-m*3^2=18m 公比=a3/a2=18m/6m=3 a2/a1=3 6m/(3m+1)=3 6m=3(3m+1) m=-1
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.