BECE Mathematics 2010 Paper

Concept:Two vectors are equal only when their corresponding components are equal.Explanation:Given $a = \dbinom{-5}{12}$ and $b = \dbinom{10x}{12}$.Since $a = b$, equate the top components and the bottom components separately.The bottom components are both $12$, so they are already equal.Now equate the top components:$$-5 = 10x$$Divide both sides by $10$:$$\frac{-5}{10} = x$$Simplify the fraction:$$x = -\frac{1}{2}$$This matches option B.Answer:$$x = -\frac{1}{2}$$Therefore, the correct option is B.