Blood urea nitrogen (BUN) is a measure of the amount of urea in the blood (R). It provides useful information about your health. The liver produces urea as a waste product of the digestion of proteins (R, R). Urea is a safe vehicle to get rid of excess nitrogen from the body.
Algebra is a branch of mathematics that substitutes letters for numbers, and an algebraic equation represents a scale where what is done on one side of the scale is also done to the other side of the scale and the numbers act as constants.
Mathematics as an interdisciplinary language and tool. Like reading and writing, math is an important component of learning and doing (using one's knowledge) in each academic discipline. Mathematics is such a useful language and tool that it is considered one of the basics in our formal educational system.