For all 3 questions, we will use the section formula.
1) 
2) 
3) 
The viewer mistakenly determined that one of the equations in the system should be 2 x + y = 28. Instead modifications should have been made before applying the equation.
<h3>What is an Equation ?</h3>
An equation is a mathematical statement formed when two algebraic expressions are equated using an equal sign.
Total Questions = 20
Total Points = 28
Correct Answers = +2 points
Incorrect Answers = -1 point
The viewer represents the correct answers with x and the incorrect ones with y.
x+y = 20
for every correct answers 2 points;
and for every incorrect answers, -1 point
This can be written as
2x-y = 28
The viewer's mistake is that; instead of subtracting total incorrect points from the correct points, the viewer added them together;
now
2x-y = 28
x+y = 20
On adding the equations
]3x = 48
x = 16
y = 4
This means that the contestant answered 16 questions correctly and 4 questions incorrectly
The viewer mistakenly determined that one of the equations in the system should be 2 x + y = 28.
To know more about Equation
brainly.com/question/10413253
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Answer:
X=9
Step-by-step explanation:
A circle adds up to 360°
63+89+73= 225
360-225= 135
Since 15x
135÷15=9
x=9
