item a)
To find the discount amount we just need to calculate 9% of $930. To calculate 9% of something, is the same as multiplying by 9/100.
[tex]930\times\frac{9}{100}=83.7[/tex]The we have our answer. The discount amount is $83.7
item b)
To find the exercise machine's sale price we just need to subtract the discount from the original price.
[tex]930-83.7=846.3[/tex]Then, the sale price is $846.3
