39 POINT BRAIN. LY QUESTION WHAAA

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

Which expression shows the sum of the polynomials with like terms grouped together

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?