BECE Mathematics 2013 Paper

Concept:The mapping has a constant difference between consecutive $y$-values, so it follows a linear rule of the form $y = mx + c$.Explanation:The $x$-values are $1, 2, 3, 4, 5$.The corresponding $y$-values are $5, 8, 11, 14, 17$.The difference between consecutive $y$-values is $8 - 5 = 3$.Because this difference is constant, the coefficient of $x$ is $m = 3$.Substitute the first pair, $x = 1$ and $y = 5$, into $y = 3x + c$.This gives $5 = 3(1) + c$.So $c = 5 - 3 = 2$.Thus, the mapping rule is $y = 3x + 2$.Verify with another pair: for $x = 3$, $y = 3(3) + 2 = 11$, which matches the table.Answer:The correct option is D. $y = 3x + 2$.