3 + (5 + 7) Use the commutative property of operations to reverse the numbers in the expression. Use the associative property of operations to change the grouping after reversing the numbers in the expression. Evaluate the expression.

Use the commutative property of operations to reverse the numbers in the expression.

✔ 3 + (7 + 5)

Use the associative property of operations to change the grouping after reversing the numbers in the expression.

✔ (3 + 7) + 5

Evaluate the expression.

✔ 15

commutative property:

A + B = B + A

So we have

3 + (5 + 7) = (5 + 7) + 3

Now distributive means that:

A + (B + C) = (A + B) + C

So (5 + 7) + 3 = 5 + (7 + 3)

now the equation is easier to solve, because 7 + 3 = 10

5 + (7 + 3) = 5 + 10 = 15