Question

(x+3)(x-3)=40
simplify quadratic equation​

Answer 1

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

$x ^{2} - 9 = 40$

$x {}^{2} - 9 - 40= 0$

$x {}^{2} - 49 = 0$

$(x - 7)(x + 7) = 0$

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

Answer 2

Step-by-step explanation:

(x+3)(x-3)=40

x^2-3^2=40 [(a+b)(a-b)=a^2-b^2]

x^2-9=40

x^2=40+9

x^2=49

x=√49

x=7

x=+7 or x=-7