The Ahmose Papyrus or the Rend Mathematical Papyrus.

 

It is the oldest manuscript written in algebra and trigonometry. It dates back to 1550 BC, meaning about 3550 years ago.

The manuscript shows that the Egyptians used first-order equations and solved them in different ways. They also knew second-order equations and they also solved them.

And they also knew numerical and geometric sequences

And they knew quadratic equations like the two

X 2 y2 = 100 y = 3/4 x, where x = 8, y = 6

And this equation is the origin of the Pythagorean theorem 

a2 = b2c2

And the Egyptians used to call the unknown number (a pile)

Pythagoras developed his mathematical theories after he traveled to Egypt

And he learned at the hands of the Egyptian priests, and this is proven in the books of Greek historians and scholars such as Porphyryus of Sour, Herodotus and Thales that the Egyptians had algebra, trigonometry, and geometry.

That's about 2000 years before Pythagoras was born.

About 3,000 years before al-Khwarizmi was born.

It is currently housed in the British Museum in London