Can someone please explain to me what the "subtraction property of equality" is?
I know what the transitive property of equality is: if a = b, and b = c, then a = c.
So for example I have a problem i'm working on where I'm proving vertical angles are congruent. I've already narrowed everything down to transitive property of equality: Angle 1 + Angle 4 = Angle 3 + Angle 4. Using the subtraction property of equality will be my final step in proving congruency, but I don't know what or how to use this property. Help please?