Question

What are the solutions of the equation (2x + 3)2 + 8(2x + 3) + 11 = 0

Answer 1

Answer:

$x=\frac{-7-\sqrt{5}}{2}$ or $x=\frac{-7+ \sqrt{5}}{2}$

Step-by-step explanation:

The given equation is

$(2x+3)^2+8(2x+3)+11=0$

Let us treat this as a quadratic equation in $(2x+3)$.

where $a=1,b=8,c=11$

The solution is given by the quadratic formula;

$(2x+3)=\frac{-b\pm \sqrt{b^2-4ac} }{2a}$

We substitute these values into the formula to obtain;

$(2x+3)=\frac{-8\pm \sqrt{8^2-4(1)(11)} }{2(1)}$

$(2x+3)=\frac{-8\pm \sqrt{64-44} }{2}$

$(2x+3)=\frac{-8\pm \sqrt{20} }{2}$

$(2x+3)=\frac{-8\pm2\sqrt{5} }{2}$

$(2x+3)=-4\pm \sqrt{5}$

$(2x+3)=-4-\sqrt{5}$ or $(2x+3)=-4+ \sqrt{5}$

$2x=-3-4-\sqrt{5}$ or $2x=-3-4+ \sqrt{5}$

$2x=-7-\sqrt{5}$ or $2x=-7+ \sqrt{5}$

$x=\frac{-7-\sqrt{5}}{2}$ or $x=\frac{-7+ \sqrt{5}}{2}$