5 = 2m − 3 what does m equal?

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

Rationalize the denominator- 12x/√x-10

Will give a: 122 b: 90 c: 48 d: 180