CORE_MATH • SHS 1Term 2WAEC / WASSCE SyllabusVIP Lesson

Simultaneous Linear Equations

Elimination method, substitution method, graphical intersection method, and practical commercial word problems.

Share Lesson with Students:
Real-World Context & Relevance in Ghana

A bakery in Takoradi producing loaves of bread and meat pies determines individual ingredient costs by tracking daily flour and butter purchases across two distinct batch days.

Key Syllabus Learning Objectives

  • 1Solve 2×2 systems of linear equations using the elimination method
  • 2Solve systems using the substitution method efficiently
  • 3Interpret simultaneous solutions graphically as intersection points of lines
  • 4Formulate and solve real-world commercial word problems
1

The Elimination Strategy

Align equations in the standard form ax + by = c. Decide which variable to eliminate. If coefficients have the same sign, subtract the equations. If coefficients have opposite signs, add them.
  • Arrange equations: a₁x + b₁y = c₁ and a₂x + b₂y = c₂.
  • Multiply to balance coefficients.
  • Same sign -> Subtract; Opposite sign -> Add.
  • Substitute the found variable back into any original equation.
Core Takeaway:

Check both solutions in BOTH original equations to ensure accuracy.

WAEC / WASSCE Examiner Tips
  • Clearly label your equations as (1) and (2) and write down the operation performed (e.g. "Subtract (2) from (1)").
  • Do not forget to find the second variable; many candidates find x and forget y, losing half the marks.
  • In word problems, translate prices or quantities into words before concluding.
Common Candidate Pitfalls & Errors to Avoid
  • Subtracting equations incorrectly when negative signs are involved.
  • Substituting the expression back into the same equation it was derived from when using substitution.
  • Finding only one variable instead of both.
Topic Mastery Checklist
  • Can I balance coefficients to eliminate x or y?
  • Can I use substitution when one variable has a coefficient of 1?
  • Can I translate a two-item shopping problem into simultaneous equations?
Test Your Knowledge

Ready for the Topic Quiz?

10 WAEC-standard multiple choice questions with instant explanations.

Start Quiz Now

Student Study Notes & Discussion

Share what you understood, ask questions, or drop helpful revision tips on Simultaneous Linear Equations.

0 Notes
0/500 characters • Keep discussions respectful and educational
Loading community notes...