Answer: The number of essay questions is 9
From the system of linear equation given
m + s = 26 --------------- equation 1
3m + 8s = 123 ----------- equation 2
where m represents the number of multiple question and s represents the number of essay question
To find the value of s, we need to isolate m in equation 1
Equation 1 becomes
m = 26 - s
Substitute the value of m in equation 2
3(26 - s ) + 8s = 123
Open the parenthesis
3 x 26 - 3 x s + 8s = 123
78 - 3s + 8s = 123
collect the like terms
-3s + 8s = 123 - 78
5s = 45
Divide both sides by 5
5s/5 = 45/5
s = 9
Therefore , the number of essay questions is 9