accounting is usefull only to owner
Answers
(i) First Find the value of LHS
Using Identity (a + b) 2 = a2 + 2ab + b2 for finding the value of 
In the given expression a = 3x and b = 6
On substituting these values in the above identity, we get

⇒  (i)
On subtracting 84x in eqn (i), we get


Now Find the value of RHS

Using Identity (a - b) 2 = a2 - 2ab + b2 for finding the value of 
In the given expression a = 3x, b = 7
On substituting these values in the above identity, we get

⇒  (ii)
Therefore from eqn (i) and eqn (ii) we found that LHS = RHS
(ii) First Find the value of LHS

Using Identity (a - b) 2 = a2 - 2ab + b2 for finding the value of 
In the given expression a = 9p, b = 5q
On substituting these values in the above identity, we get

⇒  (i)
On Adding 180pq in eqn (i), we get


Now Find the value of RHS

Using Identity (a + b)2 = a2 + 2ab + b2 for finding the value of 
In the given expression a = 9p, b = 5q
On substituting these values in the above identity, we get

⇒  (ii)
Therefore from eqn (i) and eqn (ii) we found that LHS = RHS
(iii) First Find the value of LHS

Using Identity (a - b) 2 = a2 - 2ab + b2 for finding the value of 
In the given expression a = 
On substituting these values in the above identity, we get

⇒  (i)
On Adding 2mn in eqn (i), we get


Therefore we found that LHS = RHS
(iv) First Find the value of LHS

Using Identity (a + b) 2 = a2 + 2ab + b2 for finding the value of 
In the given expression a = 4pq and b = 3q
On substituting these values in the above identity, we get

⇒  (i)
Using Identity (a - b) 2 = a2 - 2ab + b2 for finding the value of 
In the given expression a = 4pq, b = 3q
On substituting these values in the above identity, we get

⇒  (ii)
On subtracting eqn (ii) from eqn (i), we get



Therefore we found that LHS = RHS
(v) Using Identity (a + b)(a - b) = a2 - b2 (i)
Applying above identity in (b - c) (b + c), we get
 (ii)
On Applying above identity in (c - a) (c + a), we get
 (iii)
On adding eqn (i), (ii) and (iii), we get

i.e. LHS = RHS
Hence Proved!