In algebra we use letters to represent unknown numbers.
When we are writing algebra we do not use a times sign.
We can write a × b as ab
We can write 5 × c as 5c
We can write 6 × a × b as 6ab
When we have the same letter multiplied together we can use a power.
In the same way that we say the 5 × 5 = 5² we can say that a × a = a²
b × b × b = b³
p × p × p × p × p = p⁵
Example 1: Simplify: 4a × 5b
We can multiply the 4 and 5 together
4 × 5 = 20
We now have 20 × a × b
We don't write the times sign in algebra.
We write 20 × a × b as 20ab
The answer is 20ab
Example 2: Simplify: 10t × 3t
We can multiply the 10 and 3 together
10 × 3 = 30
We now have 30 × t × t
t × t = t²
30 × t² = 30t²
The answer is 30t²
We write division as a fraction
We write a ÷ b as a⁄b
Example 3: Simplify 12a³⁄4a
We can look at this question in two parts:
We have 12 ÷ 4
12 ÷ 4 = 3
We also have a³ ÷ a
a³ ÷ a = a²
The answer is 3a²
Try these:
