In Mathematics, a variable is a quantity that can change. Letters are used to represent these changing, unknown quantities in arithmetic, 4 x 2 is a short way of writing 4 + 4.
Similarly, in algebraAlgebra is a branch of mathematics that substitutes letters for numbers. Algebra is about finding the unknown or putting real-life variables into equations and then solving them., 5 x a is a short form for \( \scriptsize a \: + \: a \: + \: a \: + \: a \: + \: a \)
We usually shorten \(\scriptsize 5 \: \times \: a \: to \: 5a\)
\( \scriptsize 5a \\ \scriptsize= 5 \: \times \: a \\ \scriptsize = a \: + \: a \: + \: a \: + \: a \: + \: a \)


Example
Write down the coefficients of the following expressions:
i. 3a – 5b
ii. 6d2 +Â 2dÂ
iii. -18ab2
iv. x2 – xy3
Solution
i. The coefficient of a = 3, b = – 5
ii. The coefficient of d2 = 6, d = 2
iii. The coefficient of ab2 = -18
iv. The coefficient of x2 = 1, xy3 = -1
Responses