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

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.

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