Question

If y² + 3y - 18 ≥ 0, which of the following is true?
1. y ≤ 3 or y ≥ 0
2. y > - 6 or y < 3
3. -6 ≤ y ≤ 3
4. y ≥ 3 or y ≤ - 6

Answer 1

Correct Answer - Option 4 : y ≥ 3 or y ≤ - 6

Calculation:

y2 + 3y - 18 ≥ 0

Factorising the above equation,

y2 + 6y - 3y - 18 ≥ 0

y× (y + 6) - 3 × (y + 6) ≥ 0

(y + 6) × (y - 3) ≥ 0

∴  y ≤ (-6) and y ≥ 3