Step 10 Objective

Solve a pair of simultaneous linear equations by eliminating one variable; link a graphical representation of an equation or pair of equations to the algebraic solution.


What if pupils find this a barrier?

happy learners

Ask pupils to find all the possible solutions for one of the linear equations, for example 5x + y = 17. Similarly ask pupils to find a range of solutions for a second linear equation, say 5xy = 3.
Explore what they notice.

Repeat for other pairs – then establish a link with graphical representation.

It may be necessary for pupils to convince themselves that multiplying produces an equivalent equation – so 5x + y = 17 is equivalent to:
10x + 2y = 34
15x + 3y = 51
–5xy = –17, etc