Question 1058311
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Solve. (Enter your answers as a comma-separated list.)

y^4-10y^2+9=0
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{{{t^4-10t^2+9}}} = {{{0}}}.

Factor the left side

{{{(t^2-1)*(t^2-9)}}} = {{{0}}}.

This equation deploys in two independent equations:


1.  {{{t^2-1}}} = {{{0}}}  --->  {{{t^2}}} = 1  --->  t = +/-1,

and

2.  {{{t^2-9}}} = {{{0}}}  --->  {{{t^2}}} = 9  --->  t = +/-3.


<U>Answer</U>.  The solutions of the original equation are 1, -1, 3, and -3.
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