What is the following product?

RootIndex 5 StartRoot 4 x squared EndRoot times RootIndex 5 StartRoot 4 x squared EndRoot
4 x squared
RootIndex 5 StartRoot 16 x Superscript 4 Baseline EndRoot
2 (RootIndex 5 StartRoot 4 x squared EndRoot)
16 x Superscript 4

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