Subtract the mixed numbers by finding the common denominator. five and seven tenths minus one and two fifths equals blank

five and three tenths
four and nine tenths
four and three tenths
four and nine fifteenths

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

Give the equations of two different lines that are perpendicular to the line 3x + 4y = 7.

Evaluate the function , when d = {9, 15, 30}. r = {5, 7, 12} r = {6, 10, 15} r = {6, 10, 20} r = {5, 12, 20}