How to find x in sqrt(x+3)+sqrt(2-x)=3? Please show complete solution. Thanks so much.

1 Answer
Oct 10, 2017

x=1,\qquad x=-2

Explanation:

\sqrt{x+3}+\sqrt{2-x}=3

\Rightarrow\sqrt{x+3}=3-\sqrt{2x-2}

\Rightarrow(\sqrt{x+3})^2=(2-\sqrt{2-x})^2

\Rightarrowx+3=11-6\sqrt{2x}-x

\Rightarrow2x-8=-6\sqrt{2-x}

\Rightarrow(2x-8)^2=(-6\sqrt{2-x})^2

\Rightarrow 4x-32x+64=72-36x

\Rightarrow4x^2+4x-9=0

Quadratic Formula (Plus):

x=\frac{-4+\sqrt{4^2-4(4)(-8)}}{2\cdot4}

=1

Quadratic Formula (Minus):

x=\frac{-4-\sqrt{4^2-4(4)(-8)}}{2\cdot 4}

=-2


\therefore\quad x=1,\qquad x=-2