What is the result of the calculation (a + b)(a - b), if a=7 and b = 7?

Question

If a, b, c are three real numbers such that a + b + c = 7, a^2 + b^2 + c^2= 35 and a^3 + b^3 + C^3 = 151. Find the value of abc?

Answer 1

zero is the answer