Question

What is the solution of the equation?  Eliminate any extraneous solutions.

Answer 1

$\sqrt{3x+28}-8=x\\\\\\A.\ x=9\ \vee\ x=-4\\x=9\to L=\sqrt{3\cdot9+28}-8=\sqrt{27+28}-8=\sqrt{55}-8\\ R=9;\\L\neq R\\\\B.\ x=-9\\L=\sqrt{3\cdot(-9)+28}-8=\sqrt{-27+28}-8=\sqrt1-8=1-8=-7;\\ R=-9;\ L\neq R$

$C.\ x=-9\ \vee\ x=-4\ (see\ B.)\\\\D.\ x=-4\\L=\sqrt{3\cdot(-4)+28}-8=\sqrt{-12+28}-8=\sqrt{16}-8\\=4-8=-4\\R=-4\\L=R\\\\Answer:D.$