[a+b]=[a]+[b]

Solution for [a+b]=[a]+[b] equation:

Simplifying
[a + b] = [a] + [b]

Remove brackets around [a + b]
a + b = [a] + [b]
a + b = a + [b]
a + b = a + b

Add '-1a' to each side of the equation.
a + -1a + b = a + -1a + b

Combine like terms: a + -1a = 0
0 + b = a + -1a + b
b = a + -1a + b

Combine like terms: a + -1a = 0
b = 0 + b
b = b

Add '-1b' to each side of the equation.
b + -1b = b + -1b

Combine like terms: b + -1b = 0
0 = b + -1b

Combine like terms: b + -1b = 0
0 = 0

Solving
0 = 0

Couldn't find a variable to solve for.

This equation is an identity, all real numbers are solutions.