Answer:
3x+4=40
Explanation:
Lets take "x" as the number of students who went on the trip last year
It says "3 times" the number of seventh grade students that went on the trip last year so we know that x will be multiplied by 3
It also says 4 more than so we know that 3x+4 is gonna be part of the equation
If 40 students went on this years trip then 3x+4=40