How do you find the area of a circle?

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

Which of the following constants can be added to x2 - 3x to form a perfect square trinomial?

What is the inverse of f(x) = 6x -24