Answer:
no solution
Explanation:
Given
(21 - 3a) = 6 - a ( multiply through by 3 to clear the fraction )
21 - 3a = 18 - 3a ( subtract 21 from both sides )
- 3a = - 3 - 3a ( add 3a to both sides )
0 = - 3 ← not possible
This indicates the equation has no solution