How do you factorise x^2 - 9.
x ^ 2 - 9= x ^ 2 - 3 ^ 2It turns into 3 ^ 2Because 3 ^ 2 = 9The final answer is = ( x + 3 )( x - 3 )remember the formula :a^2 - b^2 =(a+b)(a-b)
