Simplify the rational expression?

(x^2 + 7x + 10)/(x^2 + 11x + 30)
= (x^2 + 5x + 2x + 10)/(x^2 + 6x + 5x + 30)
= [(x^2 + 5x) + (2x + 10)]/[(x^2 + 6x) + (5x + 30)]
= [x(x + 5) + 2(x + 5)]/[x(x + 6) + 5(x + 6)]
= [(x + 5)(x + 2)]/[(x + 6)(x + 5)]
= (x + 2)/(x + 6)

(x+5)(x+2)/(x+5)(x+6)= (x+2) / (x+6)