Leo is solving a quadratic equation. His first step is shown below.
Problem: 3x2 - 8 - 10x = 3(2x + 3)
Step 1: 3x2 - 10x - 8 = 6x + 9
Which two properties did Leo use to get to step 1?
I. additive property of equality
II. commutative property of addition
III. multiplicative property of equality
IV. distributive property of multiplication over addition