Question

What are the solutions of the equation (x + 2)2 + 12(x + 2) – 14 = 0? Use u substitution and the quadratic formula to solve. x = negative 8 plus-or-minus 5 StartRoot 2 EndRoot x = negative 6 plus-or-minus 5 StartRoot 2 EndRoot x = negative 4 plus-or-minus 5 StartRoot 2 EndRoot x = negative 2 plus-or-minus 5 StartRoot 2 EndRoot

Answer 1

Answer:

B. $x = -6 +/- 2\sqrt{5}$

Step-by-step explanation:

substitute u for (x+2)

$u^2+12u -14=0$

use the quadratic formula

 $\frac{-b plus-or-minus \sqrt{b^{2}- 4ac } }{2a}$

$\frac{-12 plus-or-minus \sqrt{200} }{2}$

$\frac{-12 plus-or-minus 10\sqrt{2} }{2}$

Then set everything equal to u: (x+2)

$u+2=\frac{-12 plus-or-minus 10\sqrt{2} }{2}$

u-2= -12 plus-or-minus 10 sqrt{2}/2