PLEASE HELP! I REALLY NEED HELP WITH THIS All of the following expressions are equivalent to 12w + 6, except:

-1(12w - 6)
(3 + 6w)2
6(1 + 2w)
-1(-12w - 6)

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of