SOLUTION: Quesion: Which wquation below is the quadratic equation in standard form that results whsn you substitute u+x^-2 into the equation x^-4 -32 = 4x^-2 ? Answers: (a) 1/u^2 - 4/u -

Algebra ->  College  -> Linear Algebra -> SOLUTION: Quesion: Which wquation below is the quadratic equation in standard form that results whsn you substitute u+x^-2 into the equation x^-4 -32 = 4x^-2 ? Answers: (a) 1/u^2 - 4/u -      Log On


   

Question 30331: Quesion: Which wquation below is the quadratic equation in standard form that results whsn you substitute u+x^-2 into the equation x^-4 -32 = 4x^-2 ?
Answers:
(a) 1/u^2 - 4/u -32 =0
(b) u^2 -4u -32 = 0
(c) u^4 -4u^2 -32 =0
(d) u^-2 -4u +32 = 0
(e) 1/u^2 +4/u -32 =o
Answer by Cintchr(481) About Me  (Show Source):
You can put this solution on YOUR website!
+x%5E-4+-32+=+4x%5E-2+ and +u%2Bx%5E-2+
What are we substituting u+x^-2 for? What is it equal to? I am going to assume that +u%2Bx%5E-2+ should actually be +u=x%5E-2+
First, set the first equation equal to 0
+x%5E-4+-32+-4x%5E-2+=+0+ now ... the x^-4 needs to be rewritten
+%28x%5E-2%29%5E2+-32+-4x%5E-2+=+0+ anywhere there is a x^-2 ... plug in a u
+u%5E2+-32+-4u+=+0+ put the equation in descending order
+u%5E2-4u-32+=+0+ the answer is b