30 subtracted from four times a number is 3 more than the number. What is the number?

Question

7770 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-02-12T12:56:25

$4 n - 30 = 3 + n$ $4n - 30= 3 + color(red)(n)$

Let's break this down one expression at a time. First, the word "is" means "equal to" or "=". Therefore:

"30 subtracted from four times a number" = "3 more than the number"

Next, let's name the variable or "a number" or "the number". Let's call "the number" $n$ $color(red)(n)$

"30 subtracted from four times $n$ $color(red)(n)$ " = "3 more than $n$ $color(red)(n)$ "

Then the right side of the equation can be completed. "3 more than" means to "add 3" giving:

"30 subtracted from four times $n$ $color(red)(n)$ " $= 3 + n$ $= 3 + color(red)(n)$

Next, "four times" means to "multiply" or "times" by "4" giving:

"30 subtracted from" $4 \times n$ $4 xx color(red)(n)$ $= 3 + n$ $= 3 + color(red)(n)$

Now, "30 subtracted from" this result means we need to subtract "30" from the expression giving:

$(4 \times n) - 30 = 3 + n$ $(4 xx color(red)(n)) - 30= 3 + color(red)(n)$

Or

$4 n - 30 = 3 + n$ $4n - 30= 3 + color(red)(n)$