What is the volume of tue box pictured below 5/6, 1 1/8,4/5

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

What is the value of x in the this question ?

Factor the expression using the gcf. the expression 21m−49n factored using the gcf