A binary operation Δ is defined by aΔb = a + b + 1 for any numbers a and b. Find the inverse of the real number 7 under the operation Δ, if the identity ele...

A binary operation Δ is defined by aΔb = a + b + 1 for any numbers a and b. Find the inverse of the real number 7 under the operation Δ, if the identity element is -1

Answer Details

The identity element for the operation Δ is -1, which means that for any real number a, aΔ(-1) = (-1)Δa = a. To find the inverse of 7 under the operation Δ, we need to find a number x such that 7Δx = xΔ7 = -1, which is the identity element. So, we can start by setting up the equation: 7Δx = 7 + x + 1 = xΔ7 = x + 7 + 1 = -1 Simplifying each side of the equation, we get: x + 8 = -1 and 7 + x + 1 = -1 Solving for x in the first equation, we get: x = -1 - 8 = -9 Therefore, -9 is the inverse of 7 under the operation Δ, because 7Δ(-9) = (-9)Δ7 = -1, which is the identity element.