Step by step
The question
Question: simplify 3x + 5x.
Simplify means: write it shorter, with the same value.
3x + 5x
1 Group like terms
Terms are the parts between the + and − signs.
Like terms are the same kind: same letters, same powers.
All the x terms go together.
Each colour is one kind.
like terms = same letters,
same powers
3x + 5x is 8x.
It is like 3 apples plus 5 apples: that is 8 apples.
3x + 5x = 8x
So the expression is 8x.
= 8x
2 Check
Let's check.
We pick a number for each letter: x = 2.
We put it into the start.
Start: 3 × 2 + 5 × 2 = 6 + 10 = 16
Now into our answer.
Answer: 8 × 2 = 16
Both give 16.
Same value, so 8x is right!
Both give 16
Let's look back.
First: group like terms.
Last: check.
Answer
= 8x