90%in the SIMPLEST form​

Answer! if you don’t mind, can you explain

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

Use the quadratic function to predict f(x) if x equals 8. f(x) = 25x2 − 28x + 585