Question
Factorise the following using the identity $a^2- b^2= (a + b)(a - b)$.
$9x^2- 1$
$9x^2- 1$
✓
Answer
$9x^2- 1$
$= (3x)^2- 1^2$
$= (3x - 1)(3x + 1)$
$= (3x)^2- 1^2$
$= (3x - 1)(3x + 1)$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Find the square root of the following by long division method: $974169$
→Find the square root of the following by long division method.
$27.04$
→$27.04$
Factorise the following, using the identity $a^2+ 2ab + b^2= (a + b)^2$
$x^2+ 2x + 1$
→$x^2+ 2x + 1$
How many edges are there in a: Square pyramid?
Find the value of a, if:
$pqa = (3p + q)^2- (3p - q)^2$
→$pqa = (3p + q)^2- (3p - q)^2$
The area of a square field is $325m^2$. Find the approximate length of one side of the field.
→Find $m\angle C$ in the figure. If $\overline {AB} \parallel \overline {DC} $.
→Factorise:
$z^2+19 z-150$
→$z^2+19 z-150$
How many numbers lie between the squares of the following numbers?
(i) 16 and 17 (ii) 99 and 100
(i) 16 and 17 (ii) 99 and 100
What number should be subtracted from $\frac{3}{7}$ to get $\frac{5}{4}?$
→