Anumber decreased by 5 is equal to the number times 3

Let n = "a number." We will use this to translate the words into an equation.

"A number decreased by 5" becomes n - 5

"A number times 3" becomes 3*n or 3(n) or 3n. I'm going to use the last one.

Now set them equal like the problem asks.

n - 5 = 3n

Subtract 3n from both sides and add 5 to both sides to get constants on one side of the equal sign and variables on the other:

n - 3n = 5

Combine like terms:

- 2n = 5

Divide both sides by - 2 to isolate the variable:

n = 5 / -2

Your number is

she was supposed to add the hours(38.5) and multiply the amount of money she earned(7.50) resulting in $288.75 .

correct me if i'm wrong and if it is i'm truly sorry.