I’m not sure what you mean. But if you are talking about, 3x-15=2 the answer would not be x-5 it would be x= 17/3. So that means your answer would be not true. If I’m explaining the wrong thing comment and lmk :) !
Let $x be the cost of the bench, then $x+100 is the cost of the table
x+x+100=1000
2x=900
x=450
So the cost of the bench is $450
12,000, because 11,900>11,500, so you round it up to 12,000
