A student solves the following equation:

Question

Problem: 2(x - 3) + 3x = 19
Step 1: 2x - 6 + 3x = 19
Step 2: (2x + 3x) - 6 = 19
Step 3: 5x - 6 = 19
Step 4: 5x - 6 + 6 = 19 + 6
Step 5: 5x = 25
Step 6: x = 5
What property justifies going from step 3 to step 4?
A. Distributive Property
B. Addition Property of Equality
C. Substitution Property
D. Commutative Property of Addition
E. Combine Like Terms

Answer 1

The property that justifies going from step 3 to step 4 is:

B. Addition Property of Equality

This property states that if you add the same value to both sides of an equation, the two sides remain equal. In this case, the student added 6 to both sides of the equation (5x - 6 = 19 becomes 5x - 6 + 6 = 19 + 6).