JAMB 2022 Mathematics · Question 1

Three times a certain number (x), minus 2 is less than the number minus 6.Find the possible values of x.

Options

A.x <-2
B.x>2
C.x>-2
D.x<2

Answer: A. x <-2

Explanation written with AI and checked against the answer key

Analyze the question "Three times a certain number, minus 2, is less than the number minus 6" translates to: 3x − 2 < x − 6 Concept To solve a linear inequality, collect the x terms on one side and the constants on the other. Doing the same operation to both sides keeps the inequality valid. The sign flips only when you multiply or divide by a negative number. Solution 3x − 2 < x − 6 Subtract x from both sides: 2x − 2 < −6 Add 2 to both sides: 2x < −4 Divide by 2 (positive, so the sign stays): x < −2 Check: Try x = −3. Left side: 3(−3) − 2 = −11. Right side: −3 − 6 = −9. Since −11 < −9, it works. Try x = 0. Left: −2. Right: −6. Since −2 is not less than −6, it fails, which is consistent with x < −2. Answer: x < −2, which is option A. Tip: After solving an inequality, test one number from your answer region and one from outside it. This takes about 10 seconds and catches sign errors. Also remember that "less than" means the sign points toward the smaller side, so x < −2 means x is any number smaller than −2.

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