Answer: 
<u>Remove "x" and add</u>
-2 + 9 = 7
<u>Add "x" back</u>
7 -----> 7x
Note: When adding/subtracting problems like these remove "x" and then add/subtract normaly. When you get your answer put x back.
The expression 256 + 4 is equivalent to (200 + 4) + (40+4) + (16+4) according to distributive and commutative property of addition.
Given the expression 256 + 4. This can be solved using the partial sum expressed as:
256 + 4
256 + 4
= (200 + 40 + 16) + 4
According to the commutative property, A+B = B+A
The arrangement does not affect the result. Hence;
- (200 + 40 + 16) + 4 = 4 + (200 + 40 + 16)
Using the distributive law;
- 4 +(200 + 40 + 16) = (200 + 4) + (40 + 4) + (16 + 4)
Hence the expression 256 + 4 is equivalent to (200 + 4) + (40+4) + (16+4) according to distributive and commutative property of addition.
Learn more on partial sum here: brainly.com/question/6958503