Answer:
x = 30
Explanation:
An increase of 30% can be thought of as taking 30% of the number and adding that value to the original number.
For example an increase in 20% of the number 100 is calculated by taking 20% which is 20, and then adding that to 100. So an increase in 20% is equal to 120. If we want to represent this as a single fraction or percentage, we can write it as 120% or 120/100. We get this percentage by adding 100% to our original increase in percentage value.
So in this problem, we can write an increase of 30% as 130%.
Now an increase of 130% in some number x is equal to 39.
So 130% of x = 39
130/100 * x = 39
x = 39 * 100/130
x = 3900/130 = 390/13 = 30
x = 30
Hope this helps :)