ABSTRACT
Problem 2. If a +b=w− x + y, express x as the subject
w − x + y = a + b and − x = a + b −w − y Multiplying both sides by −1 gives:
(−1)(−x) = (−1)(a + b −w − y) i.e. x = −a − b +w + y The result of multiplying each side of the equation by −1 is to change all the signs in the equation. It is conventional to express answers with positive quantities first. Hence rather than x =−a −b+w+ y, x=w+y−a−b, since the order of terms connected by + and − signs is immaterial.
