A magician is setting up a magic ball trick. she will be using some number of black balls and some number of white balls, placed in a bag. either of those numbers could be zero. let be the number of black balls she uses. let be the number of white balls she uses. there will be no other balls used.

(a) Each black ball weighs 30 grams and each white ball weighs 60 grams. For the trick to work, the magician needs the total weight of the balls to be at most 600 grams. Using those values and the variables given, write an inequality describing this constraint.