How is rewriting literal equations useful when solving problems

Atypical mre contains 1,200 calories.if the average solider eats 3 mre per day and is deployed for 15 months how many calories will be consumed by a 44 member platoon of soldiers

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

17 in long 1.3 ft wide and 8in high what is the volume