Help me with this please (khan academy)

If you apply the changes below to the linear parent function f(x)=x what is the equation of the new function vertically stretched by a factor of 3 flip over the x axis

Use the distance formula to find the distance between (-3,5) and (3,1)

Cesar bought 7 items at the candy store. he bought candy bars for $0.50 each and packs of gum for $0.95 each. he spent a total of $6.80. what system represents the solution for the number of candy bars (x) and the number of pack gum (y) purchased?