Express the following words in symbols.
(a) Add up all the scores on test X, then add up all the scores on test Y, and then add the two sums together.
(b) Add up all the scores on test G. To this, add the following: the sum obtained by squaring all the scores on test P and then adding them up.

(c) Square all the scores on test X. Add them up. From this, subtract 6 times the sum you get when you multiply each score on X by the corresponding score on Y and add them up. To this, add 4 times the quantity obtained by adding up all the scores on test X and squaring the result. To this, add twice the sum obtained by squaring each Y score and then adding them up. 

(Compare the amount of space needed to express this equation in words with the amount of space needed to express it in symbols. Do you see why summation notation is necessary?)