Question

solve the equation :

(x + 3) (x - 3) = 40​

Answer 1

Step-by-step explanation:

$2x {}^{2} = 40$

$x {}^{2} = 40 \div 2$

$x {}^{2} = 20$

$x = \sqrt{20}$

Answer 2

= x(x-3) + 3(x-3) = 40
=(x^2-3x) + (3x-9) = 40
=x^2-3x + 3x-9 = 40
=x^2-9 = 40
=x^2= 40+9
=x^2 = 49
=x =square root of 49
=x = 7