If x is a positive real number such that x 2 = 16 x 2 =16, then x 3 + x = ? x 3 + x =?

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