3 min read Jun 17, 2024

Solving the Equation (z+1)^5 = z^5

This equation might look deceptively simple, but it actually leads to some interesting insights and a surprising result. Let's explore how to solve it:

Expanding the Equation

First, we need to expand the left side of the equation using the binomial theorem:

(z+1)^5 = z^5 + 5z^4 + 10z^3 + 10z^2 + 5z + 1

Now, our equation becomes:

z^5 + 5z^4 + 10z^3 + 10z^2 + 5z + 1 = z^5

Simplifying the Equation

Subtracting z^5 from both sides, we get:

5z^4 + 10z^3 + 10z^2 + 5z + 1 = 0

Finding the Solutions

This equation is a quartic equation (an equation with the highest power of z being 4). Solving quartic equations can be complex, but in this case, we can factor out a 5:

5(z^4 + 2z^3 + 2z^2 + z + 1/5) = 0

This simplifies to:

z^4 + 2z^3 + 2z^2 + z + 1/5 = 0

Unfortunately, there is no easy way to factor this equation further to find the solutions for z. We can, however, use numerical methods or graphing calculators to approximate the solutions.


The equation (z+1)^5 = z^5 has no real solutions, meaning that there are no values for z that satisfy the equation when z is a real number. The solutions to this equation involve complex numbers, which are beyond the scope of this explanation.

This example demonstrates that even seemingly simple equations can lead to complex results, highlighting the intricacies of mathematics.