Factor completely: b^2 + 3b - 4
- A. (b + 4)(b - 1)
- B. (b - 2)(b - 3)
- C. (b + 1)(b + 2)
- D. (b + 3)(b - 1)
Correct Answer & Rationale
Correct Answer: A
To factor the expression \( b^2 + 3b - 4 \), we need two numbers that multiply to \(-4\) (the constant term) and add to \(3\) (the coefficient of \(b\)). The numbers \(4\) and \(-1\) satisfy these conditions, leading to the factors \( (b + 4)(b - 1) \). Option B, \( (b - 2)(b - 3) \), yields \( b^2 - 5b + 6\), which does not match the original expression. Option C, \( (b + 1)(b + 2) \), results in \( b^2 + 3b + 2\), also incorrect due to the wrong sign on the constant term. Option D, \( (b + 3)(b - 1) \), gives \( b^2 + 2b - 3\), which again does not match. Thus, only option A correctly factors the expression.
To factor the expression \( b^2 + 3b - 4 \), we need two numbers that multiply to \(-4\) (the constant term) and add to \(3\) (the coefficient of \(b\)). The numbers \(4\) and \(-1\) satisfy these conditions, leading to the factors \( (b + 4)(b - 1) \). Option B, \( (b - 2)(b - 3) \), yields \( b^2 - 5b + 6\), which does not match the original expression. Option C, \( (b + 1)(b + 2) \), results in \( b^2 + 3b + 2\), also incorrect due to the wrong sign on the constant term. Option D, \( (b + 3)(b - 1) \), gives \( b^2 + 2b - 3\), which again does not match. Thus, only option A correctly factors the expression.
Other Related Questions
Last weekend, 625 runners entered a 10,000-meter race. A 10,000- meter race is 6.2 miles long. Ruben won the race with a finishing time of 29 minutes 51 seconds.
The graphs show information about the top 10 runners.
Based on the histogram, which statement describes the finishing time of the runner in position 3?
- A. The finishing time was between 30 and 31 minutes
- B. The finishing time was between 33 and 34 minutes
- C. The finishing time was between 31 and 32 minutes
- D. The finishing time was between 32 and 33 minutes
Correct Answer & Rationale
Correct Answer: C
The finishing time for the runner in position 3 falls within the 31 to 32 minutes range, as indicated by the histogram. This range is supported by the data distribution, showing that the majority of runners in the top 10 finished within this timeframe. Option A is incorrect because it suggests a time between 30 and 31 minutes, which does not align with the position 3 runner's time. Option B is inaccurate, as it indicates a finishing time between 33 and 34 minutes, which is too high for this position. Option D, while close, incorrectly suggests a time between 32 and 33 minutes, which does not match the histogram data for the third place runner.
The finishing time for the runner in position 3 falls within the 31 to 32 minutes range, as indicated by the histogram. This range is supported by the data distribution, showing that the majority of runners in the top 10 finished within this timeframe. Option A is incorrect because it suggests a time between 30 and 31 minutes, which does not align with the position 3 runner's time. Option B is inaccurate, as it indicates a finishing time between 33 and 34 minutes, which is too high for this position. Option D, while close, incorrectly suggests a time between 32 and 33 minutes, which does not match the histogram data for the third place runner.
2^3 * 27^(1/3) * 1^3
- A. 54
- B. 24
- C. 72
- D. 18
Correct Answer & Rationale
Correct Answer: B
To solve the expression \(2^3 \times 27^{(1/3)} \times 1^3\), we first simplify each component. Calculating \(2^3\) gives \(8\). Next, \(27^{(1/3)}\) equals \(3\) since the cube root of \(27\) is \(3\). Finally, \(1^3\) remains \(1\). Now, multiplying these values together: \(8 \times 3 \times 1 = 24\). Option A (54) results from incorrect multiplication. Option C (72) miscalculates the values, and Option D (18) stems from misunderstanding the cube root. Thus, \(24\) is the correct outcome.
To solve the expression \(2^3 \times 27^{(1/3)} \times 1^3\), we first simplify each component. Calculating \(2^3\) gives \(8\). Next, \(27^{(1/3)}\) equals \(3\) since the cube root of \(27\) is \(3\). Finally, \(1^3\) remains \(1\). Now, multiplying these values together: \(8 \times 3 \times 1 = 24\). Option A (54) results from incorrect multiplication. Option C (72) miscalculates the values, and Option D (18) stems from misunderstanding the cube root. Thus, \(24\) is the correct outcome.
Multiply (5x - 1)(5x - 1)
- A. 25x^2 + 1
- B. 25x^2 - 1
- C. 25x^2 - 2x + 1
- D. 25x^2 - 10x + 1
Correct Answer & Rationale
Correct Answer: D
To find the product of (5x - 1)(5x - 1), we can use the formula for squaring a binomial, which states that (a - b)² = a² - 2ab + b². Here, a = 5x and b = 1. Calculating this gives: - a² = (5x)² = 25x² - 2ab = 2(5x)(1) = 10x - b² = 1² = 1 Thus, the expanded form is 25x² - 10x + 1, matching option D. Option A (25x² + 1) incorrectly omits the linear term. Option B (25x² - 1) miscalculates the constant term. Option C (25x² - 2x + 1) incorrectly computes the coefficient of the x term. Each of these options fails to accurately reflect the multiplication of the binomials.
To find the product of (5x - 1)(5x - 1), we can use the formula for squaring a binomial, which states that (a - b)² = a² - 2ab + b². Here, a = 5x and b = 1. Calculating this gives: - a² = (5x)² = 25x² - 2ab = 2(5x)(1) = 10x - b² = 1² = 1 Thus, the expanded form is 25x² - 10x + 1, matching option D. Option A (25x² + 1) incorrectly omits the linear term. Option B (25x² - 1) miscalculates the constant term. Option C (25x² - 2x + 1) incorrectly computes the coefficient of the x term. Each of these options fails to accurately reflect the multiplication of the binomials.
The daily cost, C(x), tor a company to produce x microscopes is given by the equation C(x) = 300 + 10.5x. What is the cost of producing 50 microscopes?
- A. $41,250
- B. $360.50
- C. $15,525
- D. $825
Correct Answer & Rationale
Correct Answer: D
To find the cost of producing 50 microscopes, substitute x = 50 into the cost equation C(x) = 300 + 10.5x. This yields C(50) = 300 + 10.5(50), resulting in C(50) = 300 + 525 = 825. Thus, the cost for 50 microscopes is $825. Option A ($41,250) is incorrect as it likely results from a miscalculation or misunderstanding of the equation. Option B ($360.50) underestimates the production cost by omitting the correct multiplication factor. Option C ($15,525) suggests an error in the calculation, possibly misinterpreting the coefficients in the equation.
To find the cost of producing 50 microscopes, substitute x = 50 into the cost equation C(x) = 300 + 10.5x. This yields C(50) = 300 + 10.5(50), resulting in C(50) = 300 + 525 = 825. Thus, the cost for 50 microscopes is $825. Option A ($41,250) is incorrect as it likely results from a miscalculation or misunderstanding of the equation. Option B ($360.50) underestimates the production cost by omitting the correct multiplication factor. Option C ($15,525) suggests an error in the calculation, possibly misinterpreting the coefficients in the equation.