If a wall is 12 feet long and has an area of 84 feet squared what is the height?

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field

Find the rate of change for the situation.you run 7 miles in one hour and 21 miles in three hours.

How do you figure out which order to do two step equations in? like which thing do you subtract/add/multiply/divide first? i understand that you do the opposite of whatever's shown on the opposite side, but when?