Answer:
[tex]f(x) = 0.80x[/tex]
Step-by-step explanation:
Given
[tex]x \to price[/tex]
[tex]discount \to 20\%[/tex]
[tex]coupon = \$50[/tex]
Required
The function f(x) if only the discount applies
20% discount implies that the price will be reduced by 20%.
So, the function is:
[tex]f(x) = Price - Price * Discount[/tex]
[tex]f(x) = x - x * 20\%[/tex]
Factorize
[tex]f(x) = x(1 - 20\%)[/tex]
Express percentage as decimal
[tex]f(x) = x(1 - 0.20)[/tex]
[tex]f(x) = x(0.80)[/tex]
[tex]f(x) = 0.80x[/tex]