Answer:
Part a) 
Part b) 
Step-by-step explanation:
Let
W------> the number of writing assignments that Makhaya completes
M-----> the number of math assignments that Makhaya completes
so
case A) Based on the number of minutes
-----> inequality that represent the situation based on the number of minutes
The solution is the shaded area between the positive values of W and M
see the attached figure N 1
case B) Based on the number of paper sheets
-----> inequality that represent the situation based on the number of paper sheets
The solution is the triangular shaded area between the positive values of W and M
see the attached figure N 2