Equations which represent different relationships between the same variables are called simultaneous equations.

Elimination is a technique to help solve equations simultaneously and is where one of the variables in a problem is removed.

Solving more complex simultaneous equations by elimination

Maths

In the future unit, pupils will learn how to extend their understanding of solving equations and extend this to consider inequalities. Pupils will consider a variety of inequalities and ways that their solutions can be represented.

In the prior unit, pupils learnt to solve quadratic equations by factorising and this skill will be required in this unit through manipulating two simultaneous equations to find the solutions. For pupils studying the higher content, solving quadratic equations is required if one of the simultaneous equations is a quadratic.

Simultaneous equations: 2 variables

Which multiplier would match the y coefficients for equations 1) $$15x + 4y = 12$$ and 2) $$2x + 2y = 6$$:

Which multiplier would match the x coefficients for equations 1) $$3x + 5y = 21$$ and 2) $$x + 2y = 8$$:

Which multiplier would match coefficients for either $$x$$ or $$y$$ for equations 1) $$5x + 4y = -13$$ and 2) $$10x + 2y = -44$$:

What is the value of $$y$$ for simultaneous equations $$x + 4y = 7$$ and $$2x + 3y = -1$$

What is the value of $$y$$ for simultaneous equations $$3x + 4y = 10$$ and $$2x + 2y = 4$$

What is the value of $$x$$ for simultaneous equations $$3x + 3y = 21$$ and $$2x + y = 9$$

Which equation is true for $$x = 3$$ and $$y = -2$$? 

If I add together the pair of simultaneous equations $$4x + ay = 12$$ and $$5x - ay = 26$$, what is the resulting equation? 

Which equation is true for $$x = \frac{1}{2}$$ and $$y = 2$$? 

If I add together the pair of simultaneous equations $$x + y = 28$$ and $$x - y = 12$$, what is the resulting equation? 

Which equation is true for $$x = -5$$ and $$y = -2$$? 

If I add together the pair of simultaneous equations $$2x - 3y = 30$$ and $$y -2x = 6$$, what is the resulting equation? 

This lesson will be removed by end of Summer Term 2025.

Solving more complex simultaneous equations by elimination

Lesson outcome

This lesson will be removed by end of Summer Term 2025.