They definitely can be positive they can be negative and they can have an absolute value but I would choose they both can be positive and negative
<u>Step</u><u> </u><u>1</u>
given
<u>Step</u><u> </u><u>2</u>

<u>Step</u><u> </u><u>3</u>

Reason: Reflexive property
<u>Step</u><u> </u><u>4</u>
ASA