Hint
Use the stated units and precision. Subtract the additive constant, then divide the whole result by the nonzero multiplier.
Worked solution
(a)
Subtract 8 from both sides and divide the entire result by 5.
Answer: \(\displaystyle x=\frac{y-8}{5}\)
(b)
Subtract the additive constant, then divide the whole result by the nonzero multiplier.
\(6\)
Answer: \(6\)
(c)
Subtract the additive constant, then divide the whole result by the nonzero multiplier.
\(\displaystyle \frac{1}{5}\)
Answer: \(\displaystyle \frac{1}{5}\)
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: Apply inverse operations in the correct order, keeping the numerator bracketed.
- 1 mark: Give the complete requested result, using the required units, precision and boundary inclusion.
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: Subtract the additive constant, then divide the whole result by the nonzero multiplier.
- 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: Subtract the additive constant, then divide the whole result by the nonzero multiplier.
- 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.