Forgot 1 last proof

[Geometrydude147]

Given: AL=SK Prove: AS=LK

Statements Reasons
1. AL=SK Given
2. LS=LS Reflexive
3. AL+LS=SK+LS Substitution
4. AL+LS=AS Symmetric
5. SK+LS=LK ??
6. AS=LK ??

HELP!!!

 

[Mrspi]

Given: AL=SK Prove: AS=LK

Statements Reasons
1. AL=SK Given
2. LS=LS Reflexive
3. AL+LS=SK+LS Substitution
4. AL+LS=AS Symmetric
5. SK+LS=LK ??
6. AS=LK ??

HELP!!!

Looks to me like the statement in #3 was obtained by ADDING statements 1 and 2 together....(wouldn't that be the addition property of equality, since you're adding LS to both sides of statement 1?)

You did not describe any diagram that was GIVEN for this problem...I hate to ASSUME anything, but perhaps you were given something like this?

A---------L-------S---------K

Notice that L is between points A and S. So, AL + LS = AS by what was called the "definition of between" in my last geometry textbook. I've also seen it called the "Segment Addition Postulate"

You'll need to look in your textbook to see what name is given to this relationship.

Whatever it's called, that will be your "reason" for statements 4 and 5. Then, you can SUBSTITUTE AS for AL + LS and LK for LS + SK in statement 3 to produce statement 6 (so substitution will be your reason for statement 6)