Question

-14-(-15)=I don’t know how to do this. Can you help and teach me, thanks!

Answer 1

The Solution:

We are asked to evaluate the expression below:

`-14-(-15)`

You must remember the following rules in mathematics:

`\begin{gathered} i.\text{ }+*+=+ \\ ii\mathrm{}-*+=+*-=- \\ iii\mathrm{}-*-=+ \end{gathered}`

So,

`-14-(-15)=-14-*-15=-14+15`

Observe that we have two numbers to add together, (they are -14 and +15). Note also, that they have different signs attached to them, 14 has a negative sign but 15 has a positive sign.

Rule 1:

For two numbers with different signs, you subtract the smaller number from the bigger number, and then attach the sign of the bigger number to the result.

Rule 2:

For two numbers with the same signs, you add them together, and then attach the sign of the two numbers to the result.

In the case of the question at hand, rule 1 is applicable.

So, evaluating:

`\begin{gathered} -14+15 \\ By\text{ rule 1, we shall subtract 14 from 15.} \\ 15-14=1 \\ \text{ Attaching the sign of 15 to the result above, we get} \\ +1\text{ (since the bigger number is 15 and its sign is +)} \\ \text{ Therefore,} \\ -14+15=+1=1 \end{gathered}`

Thus, the correct answer is 1