What expressions are equivalent to z+(z+6)

1) (z + z) + (z +6)

2) (z + 6) + 6

3) 2 (z + 30

It would be the number 1 because this is using distributive property. You’re adding the z to both z and 6 separately.

It wouldn’t be number 2 because there’s only one 6. You don’t know the values of the z so you can’t put another 6. It wouldn’t be number 3 because the 30 comes out of nowhere. There’s only one known value in the equation.