Model pairs of constraints with two linear equations, solve by substitution or elimination, read solutions from graphs, and interpret no-solution and infinitely-many-solution cases in context.
What you’ll learn
A solution to a system is an ordered pair that satisfies every equation in the system at the same time.
Substitution isolates a variable in one equation and replaces it in the other to reduce to one variable.
Elimination combines equations so one variable cancels, then you solve for what remains and back-substitute.
Graphically, each linear equation is a line; intersections are solutions, parallel distinct lines mean none, identical lines mean infinitely many.
Real-world systems often pair two totals or two rates; label variables clearly and interpret answers with units.