Question

Solve the following (x+3)(x-3)=40


by gud night​

Answer 1

Solution :

$\: \: \: \: \: \: (x + 3)(x - 3) = 40$

$= > {x}^{2} - {3}^{2} = 40$

$= > {x}^{2} - 9 = 40$

$= > {x}^{2} = 40 + 9$

$= > {x}^{2} = 49$

$= > x = \sqrt{49}$

$= > x = 7 \: \: \: or \: \: \: - 7.$

Answer 2

x² - 3x + 3x - 9 = 40

x² - 9 = 40

x² = 40 + 9

x² = 49

x = 7