2­6 Algebraic Proofs
Properties
Addition
Subtraction
Multiplication
Division
Reflexive: a = a
Symmetric: If a = b, then b = a
Transitive: If a = b and b = c, then a = c
Substitution: If a = b, then one can replace the other
Distribution: a(b + c) = ab + ac
Oct 11­8:33 AM
2 column proof
Solve: 2(5 ­ 3x) ­ 4(x+7)=92
Oct 11­8:52 AM
1
What property allows us to say:
If mL1 = mL2, then mL2 = mL1
If mL1 = 90 and mL2 = mL1, then mL2 = 90
If AB = RS and RS = WY, then AB = WY
If AB = CD, then 1/2 AB = 1/2 CD
If mL1 + mL2 = 110 and mL2 = mL3, then mL1 + mL3 = 110
Oct 11­8:44 AM
Given: LA ≅ LB
mLB = 2 mLC
mLC = 45
Prove: mLA = 90
Oct 11­9:03 AM
2
pg. 137
9­16, 18, 20, 24, 26
Oct 10­8:51 AM
3