Use a multiplication table to write two ratios that are equivalent to 6/8

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

Solving algebraic equations 2m+3=11

Which of the following circles have their centers in the third quadrant? check all that apply.