Please find the values of the variables also write the reasons.​

Ithink i know it but i want to be sure so can you me out ?

Layla answer 21 of the 25 questions on his history test correctly. what decimal represents the fraction of problem he answer incorrectly.

Mr. roseanne will buy 12 1/2 pounds beef for for a cookout. the price for the first 3 pounds of beef is $4.99 per pound. after that, the price is $4.49 per pound. how much will mr. roshan pay for the beef