The sum of three numbers is 81. the second number is twice the first, and the third number is six more than the second. find the number

1c-2 m405 what values are needed to make each expression a perfect square trinomial? 32 + 2x+ 2-20x + 22+5x+

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

When y’all answer can y’all explain too !