What is the constant in the expression 8x 31 5 1 7x 21 6x?

How to use order of operation in 20 divide by 4 multiply 5 = 1

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base

Barney & noblet customers can choose to purchase a membership for $25 per year members receive 10% off all store purchases 1. how much would a member pay per year if he bought $50 worth of items each year? 2. write a slope-intercept equation that expresses how much a member pays per year using x to represent his purchases per year 3. how much would a member have to spend per year to pay off his membership fee?