Hello,

I'm having trouble understanding how two terms are to be factored out in an equation. By my textbook, I have...

(1+x^{2})^{2}(-2x)-(1-x^{2})2(1+x^{2})(2x) / (1+x2)^{4 }

According to the textbook, I have to factor out like this

(1+x^{2})(2x) [(1+x^{2})(-1)-2(1-x^{2})] / (1+x2)^{4 }Anyway, silly question, but how exactly am I supposed to factor out with both 1+x^2 and 2x? Any tips?