IF YOU HELP ME‼️‼️I WILL MAKE YOU BRAINLIEST ‼️NO CAP ( well that’s only if you give me the answers to all the questions)

QUESTION 1Mike is x=20-y (x is Mike's age)Joe is z=3y-4 (z is Joe's age)QUESTION 2Just plug in 5 for yMike would be 15Joe would be 11Question 3Sally would have to be 10 years old because 10 is the only number that makes Mike age also 10. x=20-10