This simple problem can be solved using one equation
25 + 8x = 97,
8x = 97 - 25
8x = 72
x = 72/8 = 9
giving the answer 9 pounds for the weight of a single chair.
It also can be solved in one line
weight of a chair = = = 9 pounds.
I prefer this short solution.
Which way do you prefer, is your choice.
It depends on the style of teaching in your school.
In my young age, we were taught to solve such simple problems in one line.