Factor the polynomial 6d^2 - 12d

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

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

What is the equation of the line that is parallel to the line with the equation y= -3/4x +1 and passes through the point (12,-12)