SOLUTION: a number is divided by 3. then 20 is subtracted. if the result is then multiplied by 5, the product is 40. what is the number?

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: a number is divided by 3. then 20 is subtracted. if the result is then multiplied by 5, the product is 40. what is the number?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 531416: a number is divided by 3. then 20 is subtracted. if the result is then multiplied by 5, the product is 40. what is the number?
Answer by Edwin McCravy(20063) About Me  (Show Source):
You can put this solution on YOUR website!
a number is divided by 3,
Let x = "a number", so that says

x is divided by 3
And so we write that as
x%2F3

then 20 is subtracted.
That means that we are to "minus off" 20, like this
x%2F3 - 20

if the result is then multiplied by 5,
We put parentheses areound that and put a 5 in front
to multiply it by 5
5(x%2F3 - 20)

the product is 40.
So we put = 40 after that:
5(x%2F3 - 20) = 40
We divide the coefficients on both sides by 5
5%2F5(x%2F3 - 20) = 40%2F5
x%2F3 - 20 = 8
We clear of the fraction by multiplying every term by 3
3·x%2F3 - 3·20 = 3·8
    x - 60 = 24
We add 60 to both sides:
         x = 84
Edwin