What is the main difference between strict inequality and slack inequality?

Strict inequality: Inequalities of the type px + q < 0, px + q > 0, px + qy < r, px + qy > r, ax ² + bx + c > 0, or ax ² + bx + c < 0 are classified as strict inequalities. For example: 2x < − 3, x + 17 < 9, x + 3y > 14, 2a + 5b < 8, 2y ² + 5y > 8 etc.

Slack inequality: Inequalities of the type px + q ≤ 0, px + q ≥ 0, px + qy ≤ r, px + qy ≥ r, ax ² + bx + c ≥ 0, or ax ² + bx + c ≤ 0 are classified as slack inequalities. For example: x ≤ 89, 5x + 8y ≤ 9, 8x + y ≥ 7, x + 14 ≥ 28, z ² + 3z ≤ 30 etc.
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