Advertisements
Advertisements
Question
Factorise the following.
y2 + 4y – 21
Sum
Advertisements
Solution
We have,
y2 + 4y – 21
= y2 + (7 – 3)y – 21
= y2 + 7y – 3y – 21
= y(y + 7) – 3(y + 7)
= (y + 7)(y – 3)
shaalaa.com
Is there an error in this question or solution?
Chapter 7: Algebraic Expression, Identities and Factorisation - Exercise [Page 235]
APPEARS IN
RELATED QUESTIONS
The factors of x2 – 4x + 4 are __________
Expand the following square, using suitable identities
(b – 7)2
Factorise the following using suitable identity
64x2 – 112xy + 49y2
Square of 9x – 7xy is ______.
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
p2 – 2p + 1
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
a2y2 – 2aby + b2
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
`9y^2 - 4xy + (4x^2)/9`
Factorise the following.
p2 – 13p – 30
Factorise the following.
a2 – 16p – 80
If `x - 1/x = 7` then find the value of `x^2 + 1/x^2`.
