Algebraic Formulae

3.1 Algebraic Formulae

3.1

Algebraic Formulae

	Definition

	It is written in the form of an equation that combines an algebraic expression using addition, subtraction, multiplication or division.

Forming formula

Example

\(y= 3x -5\)

\(w = \dfrac{6-v}{v}\)

\(L = \dfrac{1}{2} th\)

\(A = \pi r^2\)

Changing the subject of the formula

Tips

The subject of the formula is represented by a letter.
The subject of the formula should be on the left side of the equation.

Example

Determining the value of the variable

Tips

The value of a variable in the subject of the formula can be obtained when the value of other variables is given.

Example

Given \(Q= \dfrac{2v}{-v +u}\), calculate the value of \(u\), where \(v=2, Q= 4\).

\(\begin{aligned} \\\space4 &= \dfrac{2(2)}{-2 + u} \\\\ 4 (-2 +u) &= 4 \\\\ -8 + 4u &= 4 \\\\ 4u &= 12 \\\\ u &= \dfrac{12}{4} \\\\ u &=3. \end{aligned}\)

Solving problems

Tips

It involves changing the subject of a formula, a combination of basic mathematical operations, square and square root.

Quick Notes