Which equation demonstrates the associative property of addition?

The associative property of addition states that the way in which numbers are grouped in addition does not change their sum. In other words, when adding three or more numbers, the sum remains the same regardless of how the numbers are grouped.

The equation 2 + (1 + 5) = (2 + 1) + 5 illustrates this property perfectly. In the left expression, the numbers 1 and 5 are added first, which gives a sum of 6; then 2 is added, resulting in 8. In the right expression, the grouping is changed to add 2 and 1 first, yielding a sum of 3. When 5 is added to that, the result is still 8. Since both sides of the equation lead to the same result, it demonstrates the associative property of addition effectively.

The other options pertain to different mathematical properties. The second option involves multiplication rather than addition, reflecting the associative property of multiplication. The third option is an example of the commutative property of multiplication, which focuses on the order of the numbers being multiplied. The last option represents the distributive property, which involves multiplying a number by a sum and distributing it across the terms within the parentheses. Each of these