We want to solve the following equation for $x$x: $x^4-34x^2+225=0$x4−34x2+225=0.
What substitution can we make to reduce this equation to a quadratic in the variable $p$p?
Substitute $p=x^2$p=x2 into the equation and solve for $p$p.
Now solve for $x$x using your previous answer as a reference. Write all solutions on the same line, separated by a comma.