We can apply the rules for arithmetic with rational numbers to solve problems.

In general, $a - b = a + \text- b$.

If $a - b = x$, then $x + b = a$. We can add $\text- b$ to both sides of this second equation to get that $x = a + \text- b$.

Remember: The distance between two numbers is independent of the order, while the difference depends on the order.

And when multiplying or dividing:

• A positive number multiplied or divided by a negative number always has a negative result.

• A negative number multiplied or divided by a positive number always has a negative result.

• A negative number multiplied or divided by a negative number always has a positive result.