Diophantus of Alexandria/Arithmetica/Book 1/Problem 1/100, 40

Problem

 * ''Given number $100$, given difference $40$.

Solution
The required numbers are $30$ and $70$.

Proof
Let $N$ be the given number.

Let $d$ be the given difference.

Let $x$ be the smaller of the two numbers into which $N$ is to be divided.

From the exposition of Problem $1$:

Here we have: