Like terms have same variables

Unlike terms have different variables

Let’s look at some examples

###
**
2π₯, 3π₯
**

2π₯ & 3π₯ have the same variable π₯

So they are like terms

###
**
3π₯
**
^{
2
}
**
y, 2yπ₯
**
^{
2
}

3x
^{
2
}
y has variable π₯
^{
2
}
y

2yx
^{
2
}
has variable yπ₯
^{
2
}
i.e π₯
^{
2
}
y
*
(As x
*
^{
2
}
*
y = yπ₯
*
^{
2
}
*
)
*

So, they are like terms

###
**
−4π₯y, 3xy
**

−4π₯y has variable π₯y

3π₯y has variable π₯y

−4xy and 3xy have same variable xy.

So, they are like terms.

###
**
4π₯y, 3π₯
**

4π₯y has variable π₯y

3π₯ has variable π₯

4π₯y, 3π₯ have different variables.

###
**
21z, 39z
**

21z has variable z

39z has Variable z

21z and 39z has same variable z

So, they are like terms.

###
**
8, 9
**

Since both 8 & 9 do not have a variable

∴ They are like terms

So, they are unlike terms.