Answer:
Step-by-step explanation:
<em>Let x be time, in semesters, remaining before Manuel graduates</em>.  We find that Manuel's expenses are:
$1478/semester in tuition, and
$121/semester in fees
1.  <u>x semesters remaining:  fees</u>
   Remaining cost for fees, y, is the product of the fee times the number of semesters, x:
y =($121/semester)*x
y = ($121)*x
2.  <u>x semesters remaining:  tuition</u>
   Remaining cost, y, is the product of the tuition (times the number of semesters, x.  
y = ($1478/semester)*x + ($121/semester)*x
y = ($1599)*x
3.  <u>x semesters remaining:  tuition and fees</u>
   Remaining cost, y, is the sum of the products of the tuition (times the number of semesters, and the fees (tix.  
y = ($1478/semester)*x + ($121/semester)*x
y = ($1599)*x