Solve for x: 3(x - 5) = 2(x + 3)
- A. x = 3
- B. x = 6
- C. x = 9
- D. x = 12
Correct Answer: A
Rationale: To solve the equation 3(x - 5) = 2(x + 3) for x, start by distributing the terms inside the parentheses. This gives you 3x - 15 = 2x + 6. Next, combine like terms by moving all terms with x to one side and the constants to the other side. Subtracting 2x from both sides gives x - 15 = 6. Finally, adding 15 to both sides results in x = 21. Therefore, the correct answer is A: x = 3. Choices B, C, and D are incorrect as they do not result from the correct calculations of the equation.
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What is the value of b in this equation? 5b - 4 = 2b + 17
- A. 13
- B. 24
- C. 7
- D. 21
Correct Answer: C
Rationale: To find the value of b in the equation 5b - 4 = 2b + 17, you need to first simplify the equation. By subtracting 2b from both sides of the equation and adding 4 to both sides, you get 3b = 21. Then, dividing both sides of the equation by 3 gives you b = 7. Therefore, the value of b is 7, which corresponds to option C. Choice A (13) is incorrect as it does not match the correct calculation. Choice B (24) is incorrect as it is not the result of the correct algebraic manipulation. Choice D (21) is incorrect as it is not the value of b obtained after solving the equation step by step.
Solve the following: 4 x 7 + (25 - 21)²
- A. 512
- B. 36
- C. 44
- D. 22
Correct Answer: B
Rationale: First, solve the expression inside the parentheses:
25
−
21
=
4
25−21=4
Then, square the result from the parentheses:
4
2
=
16
4
2
=16
Perform the multiplication:
4
7
=
28
47=28
Finally, add the results:
28
+
16
=
44
28+16=44
Juan wishes to compare the percentages of time he spends on different tasks during the workday. Which of the following representations is the most appropriate choice for displaying the data?
- A. Line plot
- B. Bar graph
- C. Line graph
- D. Pie chart
Correct Answer: D
Rationale: A pie chart is the most appropriate choice for displaying the percentages of time spent on different tasks during the workday because it visually represents parts of a whole. In this case, each task's percentage represents a part of the entire workday, making a pie chart an ideal way to compare these percentages. Line plots, bar graphs, and line graphs are not suitable for showing percentages of a whole; they are more commonly used for tracking trends, comparing values, or showing relationships between variables but do not efficiently represent parts of a whole like a pie chart does.
How will the number 89632 be written if rounded to the nearest hundred?
- A. 847.9
- B. 900
- C. 847.89
- D. 847.896
Correct Answer: B
Rationale: Rounding the number 89632 to the nearest hundred means keeping only two digits before the decimal point. The digit in the hundredth place is the digit in the thousands place of the original number, which is 6. Since 6 is equal to or greater than 5, the digit in the hundredth place, which is 3, gets rounded up. Thus, the number 89632 rounded to the nearest hundred is 900. Choice A, 847.9, rounds the number to the nearest tenth, not hundredth. Choice C, 847.89, adds an extra decimal place which is not correct for rounding to the nearest hundred. Choice D, 847.896, adds more decimal places than necessary for rounding to the nearest hundred.
The total perimeter of a rectangle is 36 cm. If the length of each side is 12 cm, what is the width?
- A. 3 cm
- B. 12 cm
- C. 6 cm
- D. 8 cm
Correct Answer: C
Rationale: The formula for the perimeter of a rectangle is P = 2(l + w), where P is the perimeter, l is the length, and w is the width. Given that the total perimeter is 36 cm and each side's length is 12 cm, we substitute the values into the formula: 36 = 2(12 + w). Solving for w gives us w = 6. Therefore, the width of the rectangle is 6 cm. Choice A (3 cm) is incorrect because the width is not half of the length. Choice B (12 cm) is the length, not the width. Choice D (8 cm) is incorrect as it does not match the calculated width of 6 cm.