Hint
Use the stated units and precision. Use a common denominator and add the scaled numerators.
Worked solution
(a)
Use a common denominator and add the scaled numerators.
\(\displaystyle \frac{7}{4}\)
Answer: \(\displaystyle \frac{7}{4}\)
(b)
Use a common denominator and subtract in the given order.
\(\displaystyle - \frac{1}{4}\)
Answer: \(\displaystyle - \frac{1}{4}\)
(c)
Multiply numerator by numerator and denominator by denominator.
\(\displaystyle \frac{3}{4}\)
Answer: \(\displaystyle \frac{3}{4}\)
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: Use a common denominator and add the scaled numerators.
- 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: Use a common denominator and subtract in the given order.
- 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: Multiply numerator by numerator and denominator by denominator.
- 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.