Can i get please with this please

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

If x = -2, then x 2-7x+10 equals a. 0 b.20 c.28

If chord ab is congruent to chord cd, then what must be true about ef and eg?