Advertisements
Advertisements
Question
Factorise the following.
x2 – 10x + 21
Sum
Advertisements
Solution
We have,
x2 – 10x + 21
= x2 – (7 + 3)x + 21
= x2 – 7x – 3x + 21
= x(x – 7) – 3(x – 7)
= (x – 7)(x – 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
Expand: (5x - 4)2
Factorise the following expressions
y2 – 10y + 25
Evaluate the following, using suitable identity
472
A square lawn has a 2 m wide path surrounding it. If the area of the path is 136 m2, find the area of lawn
(a – b)2 + ______ = a2 – b2
Using suitable identities, evaluate the following.
(9.9)2
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
y2 – 14y + 49
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
4y2 – 12y + 9
Factorise the following.
x2 + 4x – 77
Subtract b(b2 + b – 7) + 5 from 3b2 – 8 and find the value of expression obtained for b = – 3.
