Question 1: Evaluate the expression: when x = -3, compute 2x + 5.

Answer: -1

Question 2: Calculate the value of: -4 + (3 - x) when x = -2.

Answer: 1

Question 3: Simplify: - (6 - 2x) when x = -4.

Answer: 14

Question 4: Substitute x = -5 into the expression: 3x - (-2). What is the result?

Answer: -13

Question 5: Evaluate: - (x + 4) when x = -3.

Answer: 1

Question 6: A student incorrectly evaluates 5 - (-x) as 5 + x when x = -2. Identify the mistake and correct the evaluation.

Answer: The mistake is ignoring the negative sign. Correct evaluation: 5 - (-2) = 5 + 2 = 7.

Question 7: Solve for x: 2 - 3x = -4, with x substituted as -2. Is the substitution correct?

Answer: Yes, substituting x = -2 gives 2 - 3(-2) = 2 + 6 = 8, but original is 2 - 3x = -4, so substitute x correctly: 2 - 3(-2) = 2 + 6 = 8 ≠ -4. The substitution is incorrect for solving, but the calculation is correct for x = -2.

Question 8: Given the expression: -x + 7, evaluate when x = -8.

Answer: 15

Question 9: Construct an example where substituting a negative value into an expression results in an incorrect answer if signs are mishandled. Explain the common mistake.

Answer: A common mistake is forgetting to change the sign when substituting negative values. For example, substituting x = -3 into 2x: incorrect answer is -6 if signs are ignored; correct is 2 * (-3) = -6.

Question 10: Error analysis: A student calculates (-3)^2 as -9. Identify and explain the mistake.

Answer: The mistake is misinterpreting the exponent. (-3)^2 = 9, not -9. The negative sign is inside the parentheses, so it is squared, resulting in positive 9.

Question 11: Plot the graph of y= -2x for x from -5 to 5 on the grid.

Answer: Students draw the line y = -2x on the grid, noting the negative slope and intercept at the origin.