The steps to solve the given equation for x are shown below.
Given:
10 + 8x = 18 + 4x
Step 1: 10 + 8x + (-4x) = 18 + 40x + (-4x)
Step 2:
10 + 4x = 18 + 0
Step 3:
10 + 4x = 18
Step 4: (-10) + 10 + 4x = (-10) + 18
Step 5: 0 + 4x = 8
Step 6: 4x = 8
Select the property which is being used to write step 2.

A. multiplicative identity property

B. additive identity property

C. inverse property of addition

D. associative property