Explanation

Given:

a - b = 7

ab = 6

The formula for a³ - b³ is:

a³ - b³ = (a - b)(a² + ab + b²)

= (a - b)((a - b)² + 3ab)

Substitute the values:

a³ - b³ = 7((7)² + 3(6))

= 7(49 + 18)

= 7 × 67

= 469