certain superstores will often price match or even beat a competitor's price by 10%.the function g(x)=0.90x represents the sale price of a piece of merchandise at such a superstore.the function f(x)=0.13x represents the HST owed on a purchase with a selling price of x dollars.write a function that represents the HST owed on an item with a price tag of x dollars after it has been beaten by 10%

how much HST would be charged on a 39.99$ purchase if this price is also lowered by 10% first.

To find the HST owed on an item with a price tag of x dollars after it has been beaten by 10%, we first need to calculate the sale price after the 10% discount.

The sale price after the 10% discount is given by the function g(x) = 0.90x.

So, if the original price is x dollars, the sale price after the discount would be 0.90x dollars.

Now, we can calculate the HST owed on the sale price by using the function f(x) = 0.13x.

Substituting 0.90x into the function f(x), we get:

HST owed = f(0.90x) = 0.13 * (0.90x)

Simplifying this expression, we get:

HST owed = 0.117x

Now, to find the HST charged on a $39.99 purchase after it is lowered by 10%, we substitute x = 39.99 into the expression for HST owed:

HST owed = 0.117 * 39.99

HST owed ≈ $4.67883

Therefore, the HST charged on a $39.99 purchase, after it is lowered by 10%, would be approximately $4.68.