Let’s consider the given equation:

3 × (8 + 4) = (3 × 8) + (3 × 4)

Let’s solve both the sides of the equation.

3 × (8 + 4) = 3 x 12 = 36

(3 × 8) + (3 × 4) = 24 + 12 = 36

Notice that the product of a number and a sum is the same as multiplying each addend by the number and then adding the results.

According to distributive property of multiplication, multiplying a sum by any number is the same as multiplying each addend by the number separately and then adding the products.

a x (b + c) = ab + ac, where a, b, and c are any numbers (not equal to zero).

So, the distributive property of multiplication is used in the given equation.