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 multiple algebraic fractions

Maths

The functions unit requires pupils to write composite functions and pupils will need to draw on their understanding of how to manipulate various algebraic expressions and equations, including algebraic fractions.

In the prior unit, pupils explored various ways to manipulate and solve various equations and formulae. In this unit, pupils apply these skills to algebraic fractions in order to change the subject and manipulate the algebraic fraction.

Algebraic fractions

Make $$a$$ the subject of $$5=\frac{b+2a}{a+4}$$.

Which of these is equivalent to $$4+b=\frac{3a-4}{2b+1}$$?

Make $$a$$ the subject of $$\frac{a}{4} + \frac{3}{b}= \frac{c+2}{5}$$.

Make $$a$$ the subject of $$\frac{6b+3}{c}=\frac{4b+2}{a}$$.

Make $$a$$ the subject of $$\frac{2}{c} = \frac{2}{b} - \frac{2}{a}$$.

What is the solution to the equation $${8\over a}=6$$?

Make $$x$$ the subject of $${2\over 5x} = 3y$$.

Make $$a$$ the subject of $$x=\frac{y+5}{a-b}$$.

Which of these is equivalent to $${3x^2-12x\over x^2-9x+20}$$?

Which of these is the simplest form of $${3\over 2x+4}+{7\over 5x+10}$$?

Starter Quiz