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 | 5x^{2}y and – 4yx^{2} |
Unlike terms | 7xy^{2} and -3xy |
2)In the algebraic expression a ^{2} - 3b ^{2} + 7b ^{2} - 9a ^{2} + 6ab + 5
Like terms | Unlike terms |
a^{2} and - 9a^{2} | a^{2}and 6ab |
- 3b^{2} and 7b^{2} | 7b^{2} |
3)
Like terms | Unlike terms | Reason |
16x; 16y | Variables are not same | |
x^{2}y ; -7x^{2}y | - | 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.
(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
• Addition of algebraic expressions
• Subtraction of algebraic expressions
• Multiplication of algebraic expressions
• Division of Algebraic Expressions