Chapter 5 · Class 9 ICSE · Formula Sheet
Simultaneous Linear Equations Formulas — Class 9 ICSE
Solve pairs of linear equations using substitution, elimination, and cross-multiplication methods.
Key Formulas
Substitution
\text{Express one variable, substitute in other equation}
Elimination
\text{Make coefficients equal, add or subtract}
Cross Multiplication
\dfrac{x}{b_1c_2 - b_2c_1} = \dfrac{y}{c_1a_2 - c_2a_1} = \dfrac{1}{a_1b_2 - a_2b_1}
Worked Examples
1Using: Supplementary Angles
If one angle is 65 degrees, find its supplement.
Step 1: Supplement = 180 - 65
Step 2: = 115 degrees.
Answer: 115 degrees
2Using: Vertically Opposite
Two lines intersect. If one angle is 40 degrees, find the vertically opposite angle.
Step 1: Vertically opposite angles are equal.
Step 2: The angle = 40 degrees.
Answer: 40 degrees
Practice Now
Apply these formulas with 60+ practice questions and AI-powered doubt clearing.
More Class 9 ICSE Formulas
Frequently Asked Questions
How many formulas are in Class 9 ICSE Simultaneous Linear Equations?+
How to remember Simultaneous Linear Equations formulas easily?+
Are these Simultaneous Linear Equations formulas enough for exams?+
Master Simultaneous Linear Equations on SparkEd
Go beyond formulas. Practice at three difficulty levels with instant feedback, step-by-step solutions, and an AI coach.
Start Practising FreeSparkEd Maths provides free formula sheets for Class 1-10 across 7 education boards. All formulas are aligned to the 2025-26 syllabus.