You can
put this solution on YOUR website! .
From the problem, you have this inequality
21 + c < 36.
Subtract 21 from both sides of this inequality and get
c < 36 - 21
c < 15.
ANSWER. The additional amount which Nicole can spend is less than $15.
Solved and written for you as a mantra / (= TEMPLATE),
so you can repeat it every time as you solve similar problems.