WAEC Mathematics 2017 Paper

Concept:Removing brackets by applying the negative sign to every term inside, then combining like terms.Explanation:Start with the given expression:$$3x - (p - x) - (r - p)$$When a negative sign is before a bracket, each term inside the bracket changes its sign.So, $-(p - x)$ becomes $-p + x$.Similarly, $-(r - p)$ becomes $-r + p$.Rewriting the expression:$$= 3x - p + x - r + p$$Now combine the $x$-terms: $3x + x = 4x$.Combine the $p$-terms: $-p + p = 0$, so they cancel out.The term $-r$ remains unchanged.Therefore, the simplified expression is:$$4x - r$$Answer:$4x - r$This matches Option C.