IDNLearn.com provides a platform for sharing and gaining valuable knowledge. Get accurate and comprehensive answers from our network of experienced professionals.

What is the solution of the equation?  Eliminate any extraneous solutions.
√3x+28-8=x

 A. 9 and -4
 B. -9 
C. -9 and -4
 
D. -4


Sagot :

[tex]\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[/tex]

[tex]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.[/tex]