Author note — to cover

Solve linear pairs whose coefficients already match, adding or subtracting to remove one unknown — same signs subtract, opposite signs add — then substituting back and checking in both equations. Scaling first, substitution, worded setups and the linear-quadratic pair each have their own sibling page. Both tiers. (A19)

• Fluency — direct questions on simultaneous equations by elimination, limited to this lesson's stated scope (4 questions).
• Application — use the same skill in unfamiliar or contextual questions without introducing a later method (4 questions).
• Check — questions built around the exclusions and likely misconceptions named in the lesson brief (4 questions).