Worked solution
Solve coupled equations involving a conjugate
The complex numbers satisfy and . Find and . marks
Review: [2013/RVHS/I/7]; Lecture Example 9: [2014/RVHS/Prelim/I/7(part)] (the printed sources disagree).
CJC · Review problems · Question 3
Answer
, .
Substitute the ratio relation
The ratio requires and gives . Substitution yields . Let ; then .
Solve for the real coordinates
Compare parts: and . Multiply the first by 3 to get ; adding the second gives , hence . Substitute into : . Thus .
Find w and verify
. Check and . The source’s next line after is a substitution giving ; a duplicated “8y=16” in the extraction is a text-extraction artifact, not an extra printed equation.
Common mistakes
Conjugation changes the sign of the imaginary part only. Keep the i² contribution when expanding −3i(x+iy).
Solution notes
Source filename says 2026, but its printed header says 2025/JC2; both are retained without silently changing the source identity.
This question also appears as Lecture Example 9. Both sources give the same equations and solution. Their printed exam references disagree (2013 in the review; 2014 in the lecture); both are retained without asserting which attribution is correct.