The subject of an equation/a formula is a variable that is expressed in terms of other variables. It should have an exponent of 1 and a coefficient of 1.

Changing the subject with more complex formula

Maths

Checking and securing understanding of the distributive law with algebraic terms

Checking and securing solving linear equations

The product of two binomials

Difference of two squares

More complex binomial products

Additive relationships

Multiplicative relationships between terms

Changing the subject with simple formula

Changing the subject to suit the context

Evaluating expressions with and without changing the subject

Problem solving with expressions and formulae

In this unit, pupils use the distributive law to find the product of two binomials. In algebraic manipulation, pupils use apply this knowledge in order to factorise quadratics.

In the prior unit, pupils learnt how to rearrange an equation to find a specific value that satisfied the equation. In expressions and formulae, pupils use their understanding of rearrangement to change the subject of a formula.

This unit develops pupil understanding of formulae and how to rearrange them. Pupils will learn how to recognise and manipulate binomials and learn to recognise the difference of two squares.

Expressions and formulae

Performing the inverse operation $$\div7$$ would make $$x$$ the __________ of the equation $$7x=y.$$

Some Oak pupils are rearranging the equation $$5e-f=14$$ to make $$e$$ the subject. Who has a correct rearrangement?

Match each formula to the correct rearrangement with $$d$$ the subject.

Make $$x$$ the subject of the equation $$y=7x^2$$.

Make $$x$$ the subject of the equation $$y={7\over{x^2}}$$.

Match each formula to the correct rearrangement with $$x$$ the subject.

The subject of a formula is a variable expressed in terms of the other __________.

Because the exponent of $$x$$ is not $$1$$.

That's incorrect. $$x^2$$ is the subject of the equation.

$$x^2$$ is not the subject of the equation $$x^2=9-y^2$$. Why not?

Which of these are rearrangements of the equation $$5e-7=2d$$ ?

Which two inverse operations should you perform to both sides to solve the equation $$6x+7=49$$?

Select the expressions that are equivalent to $${1\over3}(y-5)$$.

$$d \text{ }$$ multiplied by $$5$$ then add $$2$$

$$d\text{ }$$ divided by $$5$$ then add $$2$$

$$d\text{ }$$ add $$5$$ then divided by $$2$$

$$d\text{ }$$ multiplied by $$2$$ then add $$5$$

$$d\text{ }$$ add $$2$$ then multiplied by $$5$$

$$d\text{ }$$ add $$2$$ then divided by $$5$$

Match each expression to its description.

Starter Quiz

The subject of a formula is a variable expressed in terms of the other __________.