Question

(x²-2)(x+3)+(x²+2)(x-3)=42

Answer 1

$( {x}^{2} - 2)(x + 3) + ( {x}^{2} + 2)(x - 3) = 42$
${x}^{3} + 3 {x}^{2} - 2x - 6 + {x}^{3} - 3 {x}^{2} + 2x - 6 = 42$
$2 {x}^{3} - 12 = 42$
$2 {x}^{3} = 54$
${x}^{3} = 27$
$x = 3$