Luke is 5 years younger than 3 times in sydney's age in the situation what does 3s represnt

Find the solution of this system of equation -7x+y=-20 9x-3y=36

Type the correct answer in the box. use numerals instead of words. if necessary use / for the fraction bar.

Apet store donated 50 pounds of food for adult dogs, puppies and cats to an animal shelter. 19 3/4 pounds was adult dog food and 18 7/8 pounds was puppy food. how many pounds of cat food did the pet store donate?