Question 854652
Use a substitution, {{{u=x^2}}}
{{{j(u)=u^2+7u-18}}}
{{{j(u)=(u-2)(u+9)}}}
{{{j(x)=(x^2-2)(x^2+9)}}}
{{{j(x)=(x-sqrt(2))(x+sqrt(2))(x-3i)(x+3i)}}}
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{{{x=sqrt(2)}}},{{{1}}}
{{{x=-sqrt(2)}}},{{{1}}}
{{{x=3i}}},{{{1}}}
{{{x=-3i}}},{{{1}}}