Quadratic equations - Fastest way to find the value of d

$\frac{2d^2-d-10}{d^2+7d+10} = \frac{d^2-4d+3}{d^2+2d-15}$

What is the optimal solution for finding the value of d?

• Both quadratics on the left factor, and have a common factor. Are you sure you entered the formulas correctly on the right-hand side? – rogerl Mar 16 '16 at 20:42
• @rogerl Sorry! My mistake, I typed a + instead of a - – Juanvulcano Mar 16 '16 at 20:44
• Well, now you can factor both quadratics on the right as well, and they have a common factor. That should make things much easier. – rogerl Mar 16 '16 at 20:45

Factor the quadratics. You can pull out $x+5$ on the left and $x-3$ on the right.
$$\frac{(2d-5)(d+2)}{(d+5)(d+2)} = \frac{(d-1)(d-3)}{(d+5)(d-3)}.$$