Question

A number equals four less than three times the number ?

Answer 1

See below

Explanation:

To solve this problem, you can set up the equation `x=3x-4`. Now, you must isolate the variable, or get it alone. To do this, you must add 4 to both sides.

`x+4=3x-4+4`

You are now left with `x+4=3x`. But, since we need the variable `x` by itself, you must now subtract x from both sides.

`x+4-x=3x-x`

Simplify that, and you get the equation `4=2x`. Divide both sides by `2` now, so that `x` is alone.

`4-:2=2x-:2`

Simplify, and you get your final answer of x=2.

Answer 2

The number is 2

Explanation:

This sounds rather confusing, but writing it out into an equation will help a lot in solving it.

(written:) A number equals four less than 3 times the number
(equation:) `N = 3N - 4`

Now let's isolate all parts with `N` to one side so that we can solve it. Let's subtract `3N` from both sides.
`N - 3N = cancel(3N) - cancel(3N) - 4`
`N - 3N = - 4`
`-2N = - 4`

Now let's divide by 2.
`(-2N)/2 = (- 4)/2`

`-N = - 2`

Since we have a negative sign on both sides, we can actually multiply them both by `-1` so that they will both be positive (remember that negative `xx` negative `=` positive ). This will not change their value, but it will help the answer be easier to understand.

`-N xx -1 = - 2 xx -1`

`N = 2`