Ab and c share the rent in a ratio of 4: 3: 2. the rent is ? 216. how much does a pay?

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

Find the least common multiple of the expressions: 1. 3x^2, 6x - 18 2. 5x, 5x(x +2) 3. x^2 - 9, x + 3 4. x^2 - 3x - 10, x + 2 explain if possible