We have the next information
m= number of applicantios Marko originally filled out
h= number of applications Henry originally filled out
We know that Marko originally filled out 8 more applications than Henry
m=h+8
Then each filled out 3 additional applications
m+h+6=28
Already we have a system of equations of two variables
For the question What equation can we make to represent the relationship between the number of applications Marko and Henry originally filled out.
m=h+8
Use your relationship from the equation above to create an equation representing the number of applications after completing 3 more each
(h+8)+h+6=28
The equation we can use to find the number of applications Henry and Marko each completed is
2h+14=28
We can solve the equation above
2h=28-14
2h=14
h=14/2
h=7
m=h+8=15
The number of applications Marko originally filled out is 15
The number of applications Henry originally filled out is 7