Question

How can you tell if a system of equations has infinite solutions?

Answer 1

To tell if an equation has infinite solutions, the equation will be equal to each other.

For example,

x = x
x + 1 = x + 1
x - y = x - y

And so on...

And in special cases,

0x = 0
0x = 0(y + 1)

They have infinite solutions because there's no constant to determine the variable.