Is 21.28 a rational number?

Which expression is equivalent to -5(3x - 6/7)

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

Question 3(multiple choice worth 1 points) use the arc length formula and the given information to find r. s = 16 cm, θ = 48°; r = ? sixty divided by pi cm thirty divided by pi cm one third cm one hundred twenty divided by pi cm