Question

4X square + 0X-36 by factorisation method​

Answer 1

1. By factorisation method:-

$4 {x}^{2} + 0x - 36 = 0 \\ \\ 4 {x}^{2} + 12x - 12x + 36 = 0 \\ \\ 4x(x + 3) - 12(x + 3) = 0 \\ \\ (x + 3) \: (4x - 12) = 0 \\ \\ either \: (x + 3) = 0 \: \: \: or \: \: (4x - 12) = 0 \\ \\ when \: \: \: x + 3 = 0 \\ \\ x \: = - 3 \\ \\ when \: \: \: 4x - 12 = 0 \\ \\ 4x = 12 \\ \\ x = 3$

2. You can also do it directly :-

$4 {x}^{2} - 36 = 0 \\ \\ 4 {x}^{2} = 36 \\ \\ {x}^{2} = \frac{36}{4} \\ \\ {x}^{2} = 9 \\ \\ x = \sqrt{9} \\ \\ x = + 3 \: \: or \: \: - 3$

Hope it helps.