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Show answer and solution
Solution walkthrough
- Add the equations to eliminate y: 2x = 12.
- Divide by 2, so x = 6.
SAT Math skill page
Build the SAT Math skill behind solving two equations together and translating paired constraints into a clean system.
What this tests
Dolphin question bank
Avoid these traps
A systems question usually needs both equations. One equation alone leaves too many possible values.
The SAT may ask for y, x + y, or a real-world count rather than the first variable you solve.
When subtracting equations, rewrite the full line so negative terms do not flip accidentally.
Study plan
Related practice
Skill cluster
FAQ
They appear regularly because they connect algebra, graphs, and word problems. The setup is often more important than the computation.
Use substitution when one variable is already isolated. Use elimination when coefficients line up or can be made to line up quickly.
The hardest versions hide the two equations inside a word problem or ask for an expression instead of a single variable.