Question

What is the solution set for the equation 8=x to the 2nd power -2x

Answer 1

Hi there!

$8 = {x}^{2} - 2x$
Bring all terms to the left.

$- {x}^{2} + 2x + 8 = 0$
Divide by -1.

${x}^{2} - 2x - 8 = 0$
Factoring

$(x - 4)(x + 2) = 0$
Rule AB = 0, so A = 0 or B = 0.

$x - 4 = 0$
$x = 4$

OR

$x + 2 = 0$
$x = - 2$