Advertisements
Advertisements
Question
Using the identity (a + b)(a – b) = a2 – b2, find the following product
(1 + 3b)(3b – 1)
Advertisements
Solution
(1 + 3b)(3b – 1)
(1 + 3b)(3b – 1) can be written as (3b + 1)(3b – 1)
Substituting a = 3b and b = 1
In (a + b)(a – b) = a2 – b2, we get
(3b + 1)(3b – 1) = (3b)2 – 12
= 32 × b2 – 12
(3b + 1)(3b – 1) = 9b2 – 12
APPEARS IN
RELATED QUESTIONS
Factorise the following algebraic expression by using the identity a2 – b2 = (a + b)(a – b)
9 – 4y2
The pathway of a square paddy field has 5 m width and length of its side is 40 m. Find the total area of its pathway. (Note: Use suitable identity)
Find the value of (x – y)(x + y)(x2 + y2)
Multiply the following:
(a2 – b2), (a2 + b2)
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
4x2 – 25y2
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
4x2 – 49y2
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
9x2 – 1
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
(a – b)2 – (b – c)2
Factorise the expression and divide them as directed:
(9x2 – 4) ÷ (3x + 2)
Factorise the expression and divide them as directed:
(3x4 – 1875) ÷ (3x2 – 75)
