Please someone help with this I’v been stuck on it all day

By the way I have already been sent that link that hacks you

Just show the work

Be sure to show the x and y parts and rather if their increasing or decreasing

Becca wants to mix fruit juice and soda to make a punch. she can buy fruit juice for $3 a gallon and soda for $4 a gallon. if she wants to make 28 gallons of punch at a cost of $3.25 a gallon, how many gallons of fruit juice and how many gallons of soda should she buy?