#### Answer

a.) No, one side of the equation may be negative while the other positive.
b.) No, right side is -10 while the left side is +10

#### Work Step by Step

a.) when subtracting, the Commutative Property cannot be applied.
Ex.)
3-5 = 5-3
-2 $\ne$ 2
The left side equals -2 since 3-5 = -2. The right side, however, equals 2 since 5-3 = 2.
Therefore:
a-b $\ne$ b-a
b.) We first use the Distributive Property
-2(a-5) = -2a-2(-5)
If a minus sign is next to a set of parenthesis, we can then distribute it as a -1.
-2a+10
We then determine that it cannot equal -2a-10.
-2a+10 $\ne$ 2a-10