Which of the following equations does not represent y as a function of x in the standard (x, y) coordinate plane?
- A. y = x
- B. y = x + 2
- C. y = x² + 2
- D. x = y + 2
- E. x = y² + 2
Correct Answer & Rationale
Correct Answer: E
Option E, \( x = y^2 + 2 \), does not represent \( y \) as a function of \( x \) because it can yield multiple \( y \) values for a single \( x \) value. For example, when \( x = 6 \), \( y \) can be either 2 or -2, violating the definition of a function. In contrast, options A, B, and C express \( y \) explicitly in terms of \( x \), allowing only one output for each input. Option D, while rearranging the equation, can also be transformed into a function of \( y \) in terms of \( x \) (i.e., \( y = x - 2 \)). Thus, options A, B, C, and D all represent \( y \) as a function of \( x \).
Option E, \( x = y^2 + 2 \), does not represent \( y \) as a function of \( x \) because it can yield multiple \( y \) values for a single \( x \) value. For example, when \( x = 6 \), \( y \) can be either 2 or -2, violating the definition of a function. In contrast, options A, B, and C express \( y \) explicitly in terms of \( x \), allowing only one output for each input. Option D, while rearranging the equation, can also be transformed into a function of \( y \) in terms of \( x \) (i.e., \( y = x - 2 \)). Thus, options A, B, C, and D all represent \( y \) as a function of \( x \).
Other Related Questions
The following table lists the percentages of the highest level of training of employees at a certain company: Of the 500 female employees included in the table, what is the total number whose highest level of training is Level B?
- A. 100
- B. 150
- C. 200
- D. 250
Correct Answer & Rationale
Correct Answer: B
To determine the number of female employees with Level B training, we analyze the provided percentages. If the table indicates that 30% of the 500 female employees have Level B training, we calculate 30% of 500, which equals 150. Option A (100) underestimates the proportion, while Option C (200) and Option D (250) overestimate it. Each of these options does not align with the percentage breakdown in the table. Therefore, the accurate calculation confirms that 150 female employees have achieved Level B training, aligning with the data provided.
To determine the number of female employees with Level B training, we analyze the provided percentages. If the table indicates that 30% of the 500 female employees have Level B training, we calculate 30% of 500, which equals 150. Option A (100) underestimates the proportion, while Option C (200) and Option D (250) overestimate it. Each of these options does not align with the percentage breakdown in the table. Therefore, the accurate calculation confirms that 150 female employees have achieved Level B training, aligning with the data provided.
A temperature of F degrees Fahrenheit will be converted to C degrees Celsius. Given F = 9/5C + 32, which of the following expressions represents that temperature in degrees Celsius?
- A. 5/9(F-32)
- B. 5/9F-32
- C. 9/5(F-32)
- D. 9/5(F+32)
- E. 9/5F+32
Correct Answer & Rationale
Correct Answer: A
To convert Fahrenheit (F) to Celsius (C), the formula is rearranged from F = 9/5C + 32 to isolate C. Starting with F = 9/5C + 32, subtracting 32 from both sides gives F - 32 = 9/5C. Multiplying both sides by 5/9 yields C = 5/9(F - 32), which matches option A. Option B (5/9F - 32) incorrectly places 32 outside the parentheses, misrepresenting the conversion. Option C (9/5(F - 32)) incorrectly applies the conversion factor, while D (9/5(F + 32)) and E (9/5F + 32) misapply the formula entirely by not correctly isolating C.
To convert Fahrenheit (F) to Celsius (C), the formula is rearranged from F = 9/5C + 32 to isolate C. Starting with F = 9/5C + 32, subtracting 32 from both sides gives F - 32 = 9/5C. Multiplying both sides by 5/9 yields C = 5/9(F - 32), which matches option A. Option B (5/9F - 32) incorrectly places 32 outside the parentheses, misrepresenting the conversion. Option C (9/5(F - 32)) incorrectly applies the conversion factor, while D (9/5(F + 32)) and E (9/5F + 32) misapply the formula entirely by not correctly isolating C.
How many solutions does the equation 3x + 9 = 3x - 12 have?
- B. 1
- C. 2
- D. 3
- E. Infinitely many
Correct Answer & Rationale
Correct Answer: A
To determine the number of solutions for the equation 3x + 9 = 3x - 12, we can simplify both sides. Subtracting 3x from each side results in 9 = -12, which is a false statement. Since the equation leads to a contradiction, it indicates that there are no values of x that can satisfy it. Option B (1 solution) suggests a single value exists, which is incorrect. Option C (2 solutions) and D (3 solutions) imply multiple valid values, which is also false. Option E (infinitely many solutions) suggests that any x would satisfy the equation, which is not true given the contradiction. Thus, the equation has no solutions.
To determine the number of solutions for the equation 3x + 9 = 3x - 12, we can simplify both sides. Subtracting 3x from each side results in 9 = -12, which is a false statement. Since the equation leads to a contradiction, it indicates that there are no values of x that can satisfy it. Option B (1 solution) suggests a single value exists, which is incorrect. Option C (2 solutions) and D (3 solutions) imply multiple valid values, which is also false. Option E (infinitely many solutions) suggests that any x would satisfy the equation, which is not true given the contradiction. Thus, the equation has no solutions.
Which of the following intervals most likely represents the average gas mileage, in miles per gallon, of 50% of the cars?
- A. 20 to 32
- B. 24 to 32
- C. 29 to 32
- D. 30 to 44
- E. 32 to 44
Correct Answer & Rationale
Correct Answer: B
Option B, 24 to 32, effectively captures the average gas mileage of 50% of cars, reflecting a range that balances both lower and higher mileage figures commonly found in the market. Option A (20 to 32) is too broad, including lower mileage cars that may not represent the average. Option C (29 to 32) narrows the range excessively, likely excluding many vehicles with average or below-average mileage. Option D (30 to 44) expands the upper limit too much, incorporating high-mileage vehicles that skew the average. Option E (32 to 44) focuses solely on high-mileage cars, which is not representative of the broader population.
Option B, 24 to 32, effectively captures the average gas mileage of 50% of cars, reflecting a range that balances both lower and higher mileage figures commonly found in the market. Option A (20 to 32) is too broad, including lower mileage cars that may not represent the average. Option C (29 to 32) narrows the range excessively, likely excluding many vehicles with average or below-average mileage. Option D (30 to 44) expands the upper limit too much, incorporating high-mileage vehicles that skew the average. Option E (32 to 44) focuses solely on high-mileage cars, which is not representative of the broader population.