Hint
Use the stated units and precision. Extract square factors first, then apply the stated sum, difference or product rule.
Worked solution
(a)
Extract square factors first, then apply the stated sum, difference or product rule.
\(7\)
Answer: \(7\)
(b)
Extract square factors first, then apply the stated sum, difference or product rule.
\(13\)
Answer: \(13\)
(c)
Extract square factors first, then apply the stated sum, difference or product rule.
\(252\)
Answer: \(252\)
Maths4U indicative marking guidance
Maths4U indicative marking guidance, not an official mark scheme. Credit complete valid alternative methods and consequential reasoning. An unexplained result does not earn a method mark.
(a) · 2 marks
- 1 mark: Extract square factors first, then apply the stated sum, difference or product rule.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
(b) · 2 marks
- 1 mark: Extract square factors first, then apply the stated sum, difference or product rule.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Check the answer against the original conditions.
(c) · 2 marks
- 1 mark: Extract square factors first, then apply the stated sum, difference or product rule.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
Total: 6 marks.