Answer:
10
Step-by-step explanation:
Area of traingle:1/2
50=1/2.10.x
50=5x
50/5=5x/5
50/5=5x/5
x=50/5
x=10
I think you forgot to mention Susan's current age if not:
x+5
x-4
6x
1: slope = 2/1 or 2
2: slope = 5/-5
3: slope = 3/2
4: slope = 7/-4
5: slope = 3/5
6: slope = 2/-8
7: slope = 6/2 or 3
8: slope = 2/-4
9: slope = 1/6
I believe the number of students they had last year are 360 students i hope this helps.