Ax = b, where a and b are constants.

2. Solution:

When a≠0, the equation has a unique solution:

x=b/a

When a = 0, b is not equal to zero.

The original equation is: 0x = b,

Because zero times any number is zero.

So the original equation has no solution.

When a = 0 and b = 0, the original equation is:

0x=0，

No matter what x is, this equation holds.

So the solutions of the equations are all real numbers.

For your reference, please take it.