Answer:
The viewer made a mistake in equation (2). He used 1 as coefficient of y instead of -1.
Step-by-step explanation:
It is given that, Thalia, a quiz show contestant, answered 20 questions. She was awarded 2 points for every correct answer that she gave, but she was penalized 1 point for every incorrect answer.
Let x being the number of correct answers and y being the number of incorrect answers.
...(1)
Thalia had a total of 28 points.
...(2)
On adding (1) and (2), we get
Put x=16 in (1).
The contestant answered 16 questions correctly and 4 questions incorrectly.
The viewer made a mistake in equation (2). He used 1 as coefficient of y instead of -1. Negative sign represents the deduction of penalty.