Answer:
Cost of article before tax is 120.
Step-by-step explanation:
It says cost of an article including 15% tax is 138.
So, let the cost of article without tax as 'x'
So, we can set up equation as
x+15%(x)=138
Simplify it
x+0.15x=138
1.15x=138
Divide both sides by 1.15
x=120
So, cost of article before tax is 120.
