JAMB Mathematics 2019 Paper

Concept:A compound inequality can be split into two separate inequalities, each solved using the same rules as ordinary equations.Explanation:Start with $-7 \leq 9 - 8x < 16 - x$.This means both $-7 \leq 9 - 8x$ and $9 - 8x < 16 - x$ must be true.Solve the left inequality: $-7 \leq 9 - 8x$.Subtract 9 from both sides: $-16 \leq -8x$.Divide both sides by $-8$ and reverse the inequality sign: $2 \geq x$.This gives $x \leq 2$.Solve the right inequality: $9 - 8x < 16 - x$.Subtract 9 from both sides: $-8x < 7 - x$.Add $x$ to both sides: $-7x < 7$.Divide both sides by $-7$ and reverse the sign: $x > -1$.Combine the two results: $-1 < x \leq 2$.Answer:$-1 < x \leq 2$, which is Option D.