Question

2x+4y=8

Answer 1

I assume, the task is to find the solutions of this equation.

Expressing $x$ from this equation, obtain:

$$2x = 8-4y\\ x = 4-2y$$

For any $y\in\mathbb{R}$ we can find corresponding $x\in \mathbb{R}$ using the last formula above. Thus, there are infinitely many solutions of this equation.

Answer. $x = 4-2y, y\in \mathbb{R}$.