Question

x2-3√5x-20 factorise​

Answer 1

Hello Friend.

Here is your answer below,,

$x {}^{2} - 3 \sqrt{5} x - 20 = 0 \\ = > x {}^{2} - 4 \sqrt{5} x + \sqrt{5} x - 20 = 0 \\ = > x {}^{2} - x(4 \sqrt{5} - \sqrt{5} ) - 20 = 0 \\ = > x {}^{2} - 4 \sqrt{5} x + \sqrt{5} x - 20 = 0 \\ = > x(x - 4 \sqrt{5} ) + \sqrt{5} (x - 4 \sqrt{5} ) = 0 \\ = > (x + \sqrt{5} )(x - 4 \sqrt{5} ) = 0 \\ = > x + \sqrt{5} = 0 \\ = > x = - \sqrt{5} \\ or \\ = > x - 4 \sqrt{5} = 0 \\ = > x = 4 \sqrt{5}$

I hope that helps you