Examples on Sum and Difference of Cubes
Example 1: Factorize y3 – 125
Solution:
y3 – 125 = y3 – 53
Since, a3 – b3 = (a – b) (a2 + ab + b2),
here,
- a = y
- b = 5
= (y – 5) (y2 + (y)(5) + 52)
= (y – 5) (y2 + 5y + 25)
Example 2: Evaluate 253 – 123
Solution:
Since, a3 – b3 = (a – b) (a2 + ab + b2),
where,
- a = 25
- b = 12
= 253 – 123
= (25 – 12) (252 + (25)(12) + 122)
= 13 (625 + 300 + 144)
= 13897
Example 3: Factorize 8p3 + 27
Solution:
8p3 + 27 = (2p)3 + (3)3
Since, a3 + b3 = (a + b)(a2 – ab + b2)
= (2p)3 + (3)3
= (2p + 3)[(2p)2 – (2p)(3) + (3)2]
= (2p + 3)[4p2 – 6p + 9]
Example 4: Factorize 512 + 729v3
Solution:
512 + 729v3 = (8)3 + (9v)3
Since, a3 + b3 = (a + b)(a2 – ab + b2)
= (8)3 + (9v)3
= (8 + 9v)[(8)2 – (8)(9v) + (9v)2]
= (8 + 9v)[64 – 72v + 729v2]
Example 5: Solve: 253 + 123
Solution:
Since, a3 + b3 = (a + b) (a2 – ab + b2)
where,
- a = 25
- b = 12
= 253 + 123
= (25 + 12) (252 – (25)(12) + 122)
= 37 (625 – 300 + 144)
= 17353
Sum and Difference of Cubes
The sum and difference of cubes are algebraic formulas used to factor expressions of the form a3+b3 and a3−b3 respectively. These formulas are particularly useful in simplifying and solving polynomial equations.
It is the basic formula of algebra used to solve the sum of the cubes and the difference of the cubes without actually calculating the values of the cubes. The sum of the cubes of the polynomial is represented as, a3 + b3 whereas the difference of the cubes is represented as a3– b3. These algebraic expressions are easily factorized using various algebraic expressions without actually calculating the cubes.
In this article, we will learn about Sum of Cubes, Sum of Cubes Formula, Factoring Sum of Cubes, Difference of Cubes, Difference of Cubes Formula with examples in detail below.