Question

x + 1 supra 2 = 9 supra x + 1

Answer 1

$\frac{x+1}{2} = \frac{9}{x+1} => (x+1)^{2} = 18 => x^{2} + 1 = 18 = x^{2} = 18 - 1 = x^{2} = 17$
$=> x = \sqrt{17}$

Answer 2

DVA:x ∈ R/{-1}
(x+1)(x+1)=9*2
x²+2x+1=18
x²+2x-17=0
Δ=4+68=72
x₁=-2-√72supra 2=-2-6√2supra 2=-1-3√2
x₂=-2+6√2supra 2=3√2-1