AMO 2021 - Secondary 4 (Grade 10) Question 3

Question 3

The expression $\dfrac{x^2+15x+54}{3x+27}\cdot\dfrac{6x-3}{x^2+x-30}\cdot(x^2-25)$ is well-defined. Which expression is equivalent to it?

Question illustration

$x^2+16x+15$
$x^2-8x+15$
$2x^2-15x+23$
$2x^2+9x-5$
$3x^2+48x+56$