Nokea
Simplify the expression. Which of the following is the value of x? (5(4x - 5) = (3/2)(2x - 6))
- A. −(2/7)
- B. −(4/17)
- C. (16/17)
- D. (8/7)
Correct Answer: C
Rationale: To solve the given proportion 5(4x - 5) = (3/2)(2x - 6), first distribute to get 20x - 25 = 3x - 9. Then, simplify the linear equation by isolating x: 20x - 3x = 25 - 9, which leads to 17x = 16. Finally, solving for x gives x = 16/17. Choice A is incorrect as it does not match the calculated value of x. Choice B is incorrect as it does not correspond to the correct solution for x. Choice D is incorrect as it does not align with the accurate value of x obtained from solving the equation.
You may also like to solve these questions
What is the perimeter of a rectangle with a length of 12 cm and a width of 5 cm?
- A. 17 cm
- B. 24 cm
- C. 34 cm
- D. 40 cm
Correct Answer: C
Rationale: The correct formula for the perimeter of a rectangle is P = 2(l + w), where l represents the length and w represents the width. Substituting the given values into the formula: P = 2(12 cm + 5 cm) = 2(17 cm) = 34 cm. Therefore, the perimeter of the rectangle is 34 cm. Choice A (17 cm) is incorrect as it seems to have added only the length and width without multiplying by 2. Choice B (24 cm) is incorrect as it does not consider the multiplication by 2. Choice D (40 cm) is incorrect as it seems to have added the length and width without multiplying by 2.
A sandwich shop earns $4 for every sandwich (s) it sells, $2 for every drink (d), and $1 for every cookie (c). If this is all the shop sells, which of the following equations represents what the shop's revenue (r) is over three days?
- A. r = 4s + 2d + 1c
- B. r = 8s + 4d + 2c
- C. r = 12s + 6d + 3c
- D. r = 16s + 8d + 4c
Correct Answer: A
Rationale: Let s be the number of sandwiches sold. Each sandwich earns $4, so selling s sandwiches at $4 each results in revenue of $4s. Similarly, d drinks at $2 each give $2d of income, and cookies bring in $1c. Summing these values gives total revenue = 4s + 2d + 1c. Therefore, option A, r = 4s + 2d + 1c, correctly represents the shop's revenue. Choices B, C, and D are incorrect because they incorrectly multiply the prices of each item by more than one day's sales, which would overstate the total revenue for a three-day period.
What is the result of (6.4)(2.8) · 0.4? Which of the following is correct?
- A. 16.62
- B. 17.92
- C. 41.55
- D. 44.8
Correct Answer: D
Rationale: To simplify the expression, first multiply 6.4 by 2.8 to get 17.92. Then, divide the result by 0.4 to find the final answer. Therefore, (6.4)(2.8) · 0.4 equals 44.8. Choices A, B, and C are incorrect because they do not represent the correct result of the given expression.
Solve the equation 8x − 6 = 3x + 24. Which of the following is the correct solution?
- A. x = 2.5
- B. x = 3.6
- C. x = 5
- D. x = 6
Correct Answer: D
Rationale: To solve the equation 8x − 6 = 3x + 24, start by adding 6 to both sides: 8x − 6 + 6 = 3x + 24 + 6, which simplifies to 8x = 3x + 30. Next, subtract 3x from both sides to get 5x = 30. Finally, divide both sides by 5 to solve for x: x = 6. Therefore, the correct solution is x = 6. Choices A, B, and C are incorrect because they do not result from the correct algebraic manipulation of the equation.
Which statement about the following set is true? {60, 5, 18, 20, 37, 37, 11, 90, 72}
- A. The median and the mean are equal.
- B. The mean is less than the mode.
- C. The mode is greater than the median.
- D. The median is less than the mean.
Correct Answer: D
Rationale: To find the median, we first need to arrange the set in ascending order: {5, 11, 18, 20, 37, 37, 60, 72, 90}. The median is the middle value, which is 37 in this case. The mean is calculated by adding all numbers and dividing by the total count, which gives a mean greater than 37. Therefore, the statement that the median is less than the mean is correct. Choice A is incorrect because the median and mean are not equal in this set. Choice B is incorrect as the mean is greater than the mode in this set. Choice C is incorrect as the mode is 37, which is equal to the median, not greater.