Simplify the Expression: (-x)-(+3x) Using Sign Rules

Question

Simplify the following expression:

$(-x)-(+3x)=\text{ ?}$

00:00 Simply

00:03 Negative times positive is always negative

00:06 And this is the solution to the question

Note the following rule:

$-(+x)=-x$

Now let's write the exercise in the following way:

$-x-3x=$

We'll add negative $x$ to the values on the number line and move 3 steps to the left:

Therefore, the solution is:

$-x-3x=-4x$

$-4x$