In doing math, we are actually trying to use a systematic approach to arrive at an answer. It trains the brain to trouble-shoot problems for a consistent result.
Many a times, problems or questions can be solved through guessing and checking the answers to see if they fit the original questions. It is OK.
But if the answers are guessed wrongly, many iterations of the processes take place. It does sound correct or a better way should be better.
Algebra is therefore developed to handle this issue.
See the below simple question of finding the weight of a cheese.
Here, you can see that by guessing the weight of the cheese and checking it back with the other information, you can finally obtain the correct answer.
Another way is to use algebra. This is a systematic approach that when applied, will give you the correct answer on the first try, as opposed to the guessing method.
In the above example, you can replace the weight of the items by x, y, and z.
By solving the simultaneous equations thus formed, you can easily get the answer to the weight of the cheese.
That is the power of algebra and math. No uneducated guess, and time saving as a merit.
Practice, therefore , with algebra as the need is a necessity in our daily life.