Want a million bucks? Solve this math problem

This equation of special relativity describes time dilation.

Math pays.

Texas billionaire and self-taught mathematician Andrew Beal is offering a $1 million reward to anyone who can prove what he calls the Beal Conjecture, a problem he's been trying to solve for 20 years.

In 1997, he offered $5,000 to anyone who could solve it. In 2000, he bumped up the reward to $100,000. Now he's offering seven figures to the brilliant mind who gets it right.

Even with the massive payout, the American Mathematical Society's Don McClure doesn't expect to see the conjecture solved anytime soon: "I'm not holding my breath."

The solution or a counterexample must be published in a respected mathematics journal for the solver to be eligible for the $1 million.

"I'd like to inspire young people to pursue math and science. Increasing the prize is a good way to draw attention to mathematics generally," Beal told ABC News. "I hope many more young people will find themselves drawn into the wonderful world of mathematics."

The equation is represented as Ax + By = Cz.

"The Beal Conjecture states that the only solutions to the equation Ax + By = Cz, when A, B, C, are positive integers, and x, y, and z are positive integers greater than 2, are those in which A, B, and C have a common factor," a press release explained.

While the Beal Conjecture has been around for two decades, it's by no means the oldest unsolved problem.

According to the Guinness Book of World Records, Goldbach’s Conjecture has been stumping mathematicians since 1742.