Question 339263
{{{((5x^2 + 21x + 4)/(x^2 - 16))/((5x + 1)/(x-2))}}}
{{{((5x^2 + 21x + 4)/(x^2 - 16))*((x-2)/(5x + 1))}}}  flip denominator and multiply
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{{{((5x+1)*(x+4))/((x+4)*(x-4))*(x-2)/(5x+1)}}}  factor terms
{{{(cross(5x+1)*cross(x+4))/(cross(x+4)*(x-4))*(x-2)/cross(5x+1)=(x-2)/(x-4)}}}