How to find the general term formula of the mixed sequence of equal difference and equal ratio?
Sum of arithmetic sequence: (first term + last term) x tolerance divided by 2 arithmetic sequence general term: which term = first term + (number of terms - 1) x tolerance arithmetic sequence example: original problem: in an arithmetic sequence {an}, a1 + A4 = 133, A2 + a3 = 70, find the general term formula of this sequence. A1 + A4 = A1 (1 + Q ^ 3) = 133, A2 + a3 = A1 (Q + Q ^ 2) =