Question
Factorise: $(l+3)^2-(l-m)^2$
✓
Answer
$(l+3)^2-(l-m)^2$
$= (l + m + l - m)(l + m - l + m)$
$\{\because a2 - b2 = (a + b)(a - b)\}$
$= 2l × 2m = 4lm$
$= (l + m + l - m)(l + m - l + m)$
$\{\because a2 - b2 = (a + b)(a - b)\}$
$= 2l × 2m = 4lm$
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
Using Euler’s formula. Find the value of unknown $x, y, z, p, q$ andr in the following table.
→| Faces | $6$ |
| Vertices | $q$ |
| Edges | $12$ |
How many number lie between square of the $12$ and $13?$
→Find the square root of $324$ by the method of repeated subtraction.
→Find the square root of: $10\frac{151}{225}$
→Look at the shapes given below and state these are polyhedra using Euler’s formula.
Factorise the following using the identity $a^2- b^2= (a + b)(a - b).$
$y^4- 81$
→$y^4- 81$
Observe the following pattern and the missing digits.
Factorise:
$x^2-11 x-42$
→$x^2-11 x-42$
Sawarna paid $Rs.20$ as $VAT$ on a pair of shoes worth $Rs. 250.$ Find the rate of $VAT.$
→If $123123A4$ is divisible by $11$, find the value of $A$.
→