Answer:
=9
Step-by-step explanation:
3x9=27
27/3=9
x=21/40
First get common denominators
3/8 *5 to top and bottom is now 15/40
3/20 *2 to top and bottom is now 6/40
isolate the X
x-15/40=6/40
+15/40 +15/40
1040 students will attend
Out of 80 students, 52 will attend
80/52 = 1600/ x
x=1040
