Because he added them up , instead of trying to find the mean ( average ) of his city's high temperatures.
The number of questions answered correctly = 90.
<h3>What is a system of linear equations?</h3>
- A system of linear equations is a set of two or more linear equations.
- Linear equations refer to the equations that involve two or more variables in the form of "ax + b".
Now,
Given:
- Total number of questions = 200
- Marks for correct answer = 4
- Marks for incorrect answer = -1
- Total marks = 250
To find : Number of correct answers = ?
Finding:
Now, assuming that the student attempted and answered all the questions,
- Let the number of questions correctly answered be x and incorrectly answered be y.
Then,
- x + y = 200 (For number of questions) (eqn 1)
- and 4x - y = 250 (For the marks scored) (eqn 2)
Solving the system of linear equations:
For eqn 2, we get that y = 4x - 250
Substituting in eqn 1, we get:
=> x + 4x - 250 = 200
=> 5x = 250 + 200 = 450
=> x = 90
That is, the number of questions answered correctly = 90, the incorrect answers = 200 - 90 = 110.
To learn more about system of linear equations, refer to the link: brainly.com/question/2226590
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Answer: .12 grams of butter per cupcake
Step-by-step explanation:
Answer:
Step-by-step explanation:
Given
Required
Solve for d
Collect Like Terms
Take LCM
Make d the subject
Answer:
The value of x , y using substitution method is 2 , 5
Step-by-step explanation:
Given as :
The two linear equation as
6 y - 4 x = 22 .......1
y + 2 x = 9
Let y = 9 - 2 x .......2
Now, using substitution method
Substitute the value of y from eq 2 into eq 1
i.e 6 × (9 - 2 x) - 4 x = 22
Or, 54 - 12 x - 4 x = 22
Or, 12 x + 4 x = 54 - 22
Or, 16 x = 32
∴ x = 
i.e x = 2
Now, Put the value of x into eq 2
∴ y = 9 - 2 x
So, y = 9 - 2 × 2
Or, y = 9 - 4
i.e y = 5
So, The value of x , y = 2 , 5
Hence, The value of x , y using substitution method is 2 , 5 Answer
