Back to Strand ReviewSystems & Inequalities Strand

Systems & Inequalities

Build confidence with intersections, algebraic solving, constraints, and feasible regions.

What you will practice

  • Solve systems of linear equations by graphing, substitution, and elimination.
  • Identify solutions as ordered pairs that make both equations true.
  • Interpret intersection points in real-world contexts.
  • Graph linear inequalities using boundary lines and shaded regions.
  • Use constraints to decide whether ordered pairs are feasible solutions.

Why it matters

Systems and inequalities help students connect algebra to choices, limits, and real situations. The key is knowing whether the answer is one point, no point, the same line, or a whole shaded region.

Student-friendly anchor

A system solution is the point that works in both relationships. For inequalities, graph the boundary first, then shade the side with points that make the inequality true.

What NC Math 1 expects

Based on the Math 1 standards for systems, constraints, and linear inequalities.

NC.M1.A-CED.3

Represent constraints with equations or inequalities and interpret feasible solutions in context.

NC.M1.A-REI.5

Use equivalent systems to explain why elimination keeps the same solution set.

NC.M1.A-REI.6

Solve systems of linear equations exactly or approximately using graphs and algebra.

NC.M1.A-REI.12

Graph linear inequalities in two variables and interpret solution regions.

Words and ideas to know

These terms support graphing, algebraic solving, and constraint questions.

System of Equations

Two or more equations considered at the same time. A solution must work in every equation.

Solution

An ordered pair, such as (2,4), that makes both equations or inequalities true.

Intersection Point

The point where two graphs meet. For two lines, it is the solution to the system.

Substitution

A solving method where one expression, such as y=2x+3, is placed into the other equation.

Elimination

A solving method where equations are added or subtracted so one variable cancels.

No Solution

A system with parallel lines that never intersect.

Infinitely Many Solutions

A system where both equations describe the same line.

Boundary Line

The line that separates the plane for an inequality, such as x+y=10.

Shaded Region

The side of an inequality graph containing all points that make the inequality true.

Feasible Solution

An ordered pair that satisfies every constraint in a real-world system.

Solid Boundary

Used for inequalities with \le or \ge, because boundary points are included.

Dashed Boundary

Used for inequalities with < or >, because boundary points are not included.

How to think through systems and inequalities

Decide what the question is asking for before choosing a strategy.

Graphing systems

The solution is where the two lines intersect. If the lines do not meet, there is no solution.

Substitution

If one equation already says y=2x+3, substitute that expression for y in the other equation.

Elimination

Add or subtract equations when opposite terms can cancel, such as +y and -y.

Inequalities

Use a solid boundary for \le or \ge. Use a dashed boundary for < or >.

Choose a Systems & Inequalities set

Start with DOK 1 fluency, then build toward applications, analysis, and EOC-style mixed practice.