Answer: If this case, you would have to write an expression to represent their market share. It could be 1.2x.
Since we don't know the actual amount of their current market share, we will have to use a variable. Let x = their current market share.
The problem states that it will grow by 20% or 0.2. Therefore, we just need to multiply the current amount, x, by 1 plus the extra 20% or just 1.2.