Let's go through each question step by step and provide the correct responses:
Question 1
Which equation has the same solution for x as this equation: x - 12 = 40? To solve for x from the given equation, we can rewrite it as: \[ x = 40 + 12 \] \[ x = 52 \]
We can check which responses will yield the same solution:
- x/4 = 13 → x = 52 (This is correct)
- x + 12 = -40 → x = -52 (Incorrect)
- x/2 = 14 → x = 28 (Incorrect)
- 12 - x = 40 → x = -28 (Incorrect)
Correct response: x/4 = 13
Question 2
Length of the rectangle expression: Given that the length (L) is four meters less than twice its width (W): \[ L = 2W - 4 \]
The formula for the area of a rectangle is: \[ A = L \times W \] So, \[ 96 = (2W - 4) \times W \]
Using trial and error:
- Test values for W:
- If W = 8: L = 2(8) - 4 = 12 → Area = 8 * 12 = 96 (Correct)
Responses:
- Expression for length in terms of width: 2W - 4
- Formula for the area of a rectangle: Area = L × W
- Length and width: Length = 12 m, Width = 8 m
Question 3
Match the equations with their solutions:
- 3i + 5 = 3i + 7: No solution (since 5 cannot equal 7).
- 3i + 2i - 7 = 18: Solution is i = 4 (or 3i - 2i = 18 + 7).
- 3i + 5 = 2i - 7: Solution is i = -12.
- 3(2i + 7) = 6i + 21: True for all i (identity).
- 3(2i − 7) = 15: Solution is i = 4.
Match:
- 3i + 5 = 3i + 7 → No Solution
- 3i + 2i - 7 = 18 → i = 4
- 3i + 5 = 2i - 7 → i = -12
- 3(2i + 7) = 6i + 21 → All i
- 3(2i − 7) = 15 → i = 4
Question 4
Solve the equation and justify each step:
- Step 1: Distributive Property → \(2(x + 8) = 2x + 16\)
- Step 2: Combine Like Terms to get \(2x + 16 = 2x + 8\)
For this equation, there are:
- No solutions (because the simplified form leads to a contradiction).
Question 5
Match the description of the one variable equation with the number of solutions
- x - 7 = 7 - x: One solution (x = 7).
- 3(x + 5) = 3x + 5: Infinite solutions (identity).
- 10 − x = 25: One solution (x = -15).
- 2(x + 4) = 2x + 5 + 3: No solution (leads to a contradiction).
Question 6
Inequality for student spending: The total amount spent can be expressed as: \[ 24 + 2n \leq 37 \]
Correct response: 37 ≥ 2n + 24
Question 7
Solve for b in the equation A = 12(a + b): To isolate b, rearranging gives: \[ b = \frac{A}{12} - a \]
Correct response: None of the provided responses are correct, the right form should have been \( b = \frac{A}{12} - a \).
Question 8
Solve the inequality: \(-3x + 1 ≤ -47\)
- Subtract 1 from both sides: \[ -3x ≤ -48 \]
- Divide by -3 (remember to flip the inequality): \[ x ≥ 16 \]
Question 9
Student's mistake on inequality graph for -4<x: Correct: The student did not make a mistake; this graph represents the proper solution to \(x > -4\).
Question 10
Property that justifies the step from step 3 to step 4:
- Addition Property of Equality
Question 11
Identifying mistake in solving equation:
- Property used in Step 1: Distributive Property.
- Mistake in Step 3: Correct should have been 3x=15.
- Correct answer for x should be x=5.
Question 12
Grandma's garden weed problem:
- Equation: \(250 - 5t = 30\)
- Solution: \(t = 44\) minutes.
- Meaning: It takes 44 minutes for her to get down to 30 weeds remaining.
Question 13
Solve the formula F=9/5C+32 for C:
- Subtract 32 from both sides: \(F - 32 = \frac{9}{5}C\).
- Multiply both sides by \(\frac{5}{9}\) to solve for C.
Correct option: \(C = \frac{5}{9}(F - 32)\).
With these responses, you should have the answers to all questions. If any specific question needs more detailed expansion or clarification, let me know!