Answer:
9 essay questions.
Step-by-step explanation:
Let x be the number of multiple choice questions and y be the number of essay questions.
We have been given that Diego’s history teacher writes a test for the class with 26 questions. We can represent this information in an equation as:
[tex]x+y=26...(1)[/tex]
We are also told that multiple choice worth 3 points each, so total number of points for x questions will be 3x.
As essays worth 8 points each, so total number of points for y questions will be 8y.
Since the test is worth 123 points, so we can represent this information in an equation as:
[tex]3x+8y=123...(2)[/tex]
Now we will use substitution method to solve system of linear equations.
From equation (1) we will get,
[tex]x=26-y[/tex]
Substituting this value in equation (2) we will get,
[tex]3*(26-y)+8y=123[/tex]
[tex]78-3y+8y=123[/tex]
[tex]78+5y=123[/tex]
Let us subtract 78 from both sides of our equation.
[tex]78-78+5y=123-78[/tex]
[tex]5y=45[/tex]
Let us divide both sides of our equation by 5.
[tex]\frac{5y}{5}=\frac{45}{5}[/tex]
[tex]y=9[/tex]
Therefore, there were 9 essay questions in the test.