Find this polynomial expression 8x^2+2x-15

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

An object in geometry with no width, length or height is a(n):

What are the excluded values? m+5/mn+3m