# Like and Unlike Terms

In this section we will discuss about like and unlike terms in solving algebraic expressions.

Like terms : The terms having the same literal (variable) with same exponents are called Like terms.

Example: 1) 12x and -5x 2) 4x 2 and ½ x 2

Unlike terms : The terms having the same variable with different exponents or different variable with same exponents are called Unlike terms .

Example : 1) 5x and 5y 2) 2x 2 and 3y 2

Some more examples :

1)In the algebraic expression 5x
2 y + 7xy 2 -3xy – 4yx 2
 Like terms 5x2y and – 4yx2 Unlike terms 7xy2 and -3xy

2)In the algebraic expression a
2 - 3b 2 + 7b 2 - 9a 2 + 6ab + 5

 Like terms Unlike terms a2 and - 9a2 a2and 6ab - 3b2 and 7b2 7b2

3)
 Like terms Unlike terms Reason 16x; 16y Variables are not same x2y ; -7x2y - Variables as well as exponents are same - 9ab ; - 6b 1st term contains ab and 2nd term contains 'b' only

Note: Only like terms can be added or subtracted.

Practice

(Q.1) Sate whether a given pair of terms is of like or unlike terms.
(a) 23, 203
(b) 12mn, 12m
2 n 2
(c) 3pr
2 , 12pr 2
(d) 2x, 3y
(e) 14ab, 21ab
(f) –3x, x
(g) 4x
2 + 3y 2 -2x 2 + y 2
(h) -2a
2 + 5b 2 -a 2 + b 3
(i) 12, 13a, -1/2b, a, -1/2

Algebraic Expressions

Like and Unlike terms in Algebra