Find all values of c such that c/(c - 5) = 4/(c - 4). if you find more than one solution, then list the solutions you find separated by commas.

Ametalworker has a metal alloy that is 30? % copper and another alloy that is 55? % copper. how many kilograms of each alloy should the metalworker combine to create 90 kg of a 50? % copper? alloy?

Find the solution set of this inequality. enter your answer in interval notation using grouping symbols. |8x-4| ≤ 12

Acontainer holds 0.7 liters of oil and vinegar. 3/4 of the mixture is vinegar. how many liters of oil are in the container? express your answer as both a fraction and a decimal.