It is known that: a = B + 2, the absolute value of C is 3, m, n are reciprocal, try to find the algebraic formula (a-b) / 5 + 4mn-c ^ 2

It is known that: a = B + 2, the absolute value of C is 3, m, n are reciprocal, try to find the algebraic formula (a-b) / 5 + 4mn-c ^ 2

Because: a = B + 2, the absolute value of C is 3, m, n reciprocal each other
So: A-B = 2, C ^ 2 = 9, Mn = 1
Then: (a-b) / 5 + 4mn-c ^ 2 = 2 / 5 + 4-9 = - 5 / 2