Step by step
The question
Question: find the value of 3(x − 2) when x = 7.
3(x − 2)
x = 7
1 Put the numbers in
We put 7 in place of x.
3(x − 2) means 3 times (x − 2).
So we write a times sign.
= 3 × (7 − 2)
3(x − 2) = 3 × (x − 2)
2 Brackets first
Brackets come first.
Order: ( ) → x² √ → × ÷ → + −
7 minus 2 is 5.
= 3 × 5
3 Times and divide
3 times 5 is 15.
= 15
So 3(x − 2) is 15 when x = 7.
Let's look back.
First: put the numbers in.
Then: brackets first.
Last: times and divide.
Answer
= 15