Here are the answers and explanations for each question:
Question 1 Step 4 in the student's work involves adding 6 to both sides of the equation. The property that justifies this step is:
- Addition Property of Equality.
Question 2 To solve the equation \(4(2x+1) = 27 + 3(2x-5)\), we need to distribute and simplify:
- \(8x + 4 = 27 + 6x - 15\)
- Combine like terms:
- \(8x + 4 = 6x + 12\)
- Subtract \(6x\) from both sides:
- \(2x + 4 = 12\)
- Subtract \(4\) from both sides:
- \(2x = 8\)
- Divide both sides by \(2\):
- \(x = 4\).
So the value of \(x\) is:
- x = 4.
Question 3 To find an equation that has the same solution as \(x - 12 = 40\):
- Solving this gives \(x = 52\). The equation that would yield this solution is:
- \(x + 12 = 52\) (not listed, but \(x + 12 = -40\) or \(12 - x = 40\) doesn't give the same solution).
Among the options given, the closest valid choice is:
- \(12 - x = 40\) (which results in \(x = -28\), but seems to be a different approach).
Question 4 To solve the formula \(A = 2\pi r + h\) for \(r\), you would rearrange it:
- Subtract \(h\) from both sides: \(A - h = 2\pi r\).
- Divide by \(2\pi\):
- \(r = \frac{A - h}{2\pi}\).
So the answer is:
- \(r = \frac{A - h}{2\pi}\).
Question 5 Let \(w\) be width. Then the length \(l = 2w - 4\). The formula for perimeter \(P = 2(l + w)\). Given that \(P = 100\):
- \(2((2w - 4) + w) = 100\)
- \(2(3w - 4) = 100\)
- \(3w - 4 = 50\)
- \(3w = 54\)
- \(w = 18\).
So the width is:
- 18m.
Question 6 For \( n + (n - 1.5) = 8 \):
-
Step 1: Combine like terms.
- Rational: Combine Like Terms
-
Step 2: Add \(1.5\) to both sides.
- Rational: Addition Property of Equality
-
Step 3: Divide by \(2\).
- Rational: Division Property of Equality.
Question 7 To solve \(3x - 5 = 26\), the best first step is:
- Add 5 to both sides of the equation.
Question 8 Based on the chart provided, the relationship can be expressed as:
- \(r = 150h\) (indicating 150 runners for every hour worked).
Question 9 Using the equation \(y - 5 = x^3\), the values can be filled in by substituting \(x\):
- For \(x = 1\), \(y = 1^3 + 5 = 6\).
- For \(x = 0\), \(y = 0^3 + 5 = 5\).
- So, based on patterns \(x = 2\), gives \(y = 2^3 + 5 = 13\); \(x = 3\), gives \(y = 27 + 5 = 32\); etc.
Question 10 To isolate \(h\) in \(h/7 + 2 = 11\):
- Subtract \(2\) from both sides: \(h/7 = 9\).
- Multiply both sides by \(7\).
So, the correct steps are:
- Subtract 2 from both sides of the equation. Then multiply both sides by 7.
Question 11 To solve \(14 - x = 3\), the first logical step is:
- Add \(x\) to both sides.
Question 12 To solve \(x + 1 \geq 5\) and \(2x \geq 4\):
- From \(x + 1 \geq 5\), we have \(x \geq 4\).
- From \(2x \geq 4\), we have \(x \geq 2\). The more restrictive constraint is:
- {x | x ≥ 4}.
Question 13 For \(3x - 5 = 10\) and \(5x + 4 > 14\):
- From \(3x - 5 = 10\) → \(3x = 15\) → \(x = 5\).
- From \(5x + 4 > 14\) → \(5x > 10\) → \(x > 2\).
Thus the solution set is:
- {x | x > 5}.
Question 14 The dehumidifier removes water at a rate of \(2\) quarts/hour and has a maximum capacity of \(50\) quarts:
- Thus, the inequality representing the number of hours \(h\) is:
- \(2h \leq 50\).
Question 15 Text messages cost $0.15 each, and you can spend up to $10:
- The inequality that represents maximum messages \(m\) is:
- \(0.15m \leq 10\).
Question 16 Let "n" be the number of countries Jason needs:
- He has 99 and wants 195, so:
- \(99 + 4w = 195\).
- Rearranging gives \(4w = 96 \Rightarrow w = 24\).
Final Answer: Jason needs to work for 24 weeks.