>>123474791. distributive law: a(b+c) = ab + ac
2. Inverse addition: b - b = 0
3. Additive identity: a + 0 = 0
a(0 + 0) = a(0) = a(0) + a(0)
a(0) - a(0) = a(0) + a(0) - a(0)
a(0) = 0
a(b - b) = 0
ab - ab = 0 (positive times negative is negative)
-a(b - b) = 0
-ab + ab = 0 (negative times negative is positive)
