Question

Factorise x^2-900 and c^2-64 fully​

Answer 1

Explanation:
Question 1)

Rewrite 900 as 30²:

`x^(2) -30^(2)`

Use D.O.T.S (difference of two squares) formula
`x^(2) -y^(2) =(x+y)(x-y)` :

`x^(2) -30^(2) = (x+30)(x-30)`

Answer 1) (x+30)(x-30)

Question 2)

Rewrite 64 as 8²:

`c^(2) -8^(2)`
Use D.O.T.S (difference of two squares) formula
`x^(2) -y^(2) =(x+y)(x-y)` :

`c^(2) -8^(2) = (c+8)(c-8)`
Answer 2) (c+8)(-8)