Hi, I don’t get these types of problems & would really like an explanation for their solution. (x- 3)(x – d) = x^2 – 2dx + m. I don’t know how to find the value of dm because I can’t isolate d without getting a fraction. Please help );
The thing to remember on a question like this is that when you have equivalent polynomials, the coefficients of each term are equal. Step 1 is to expand the left hand side.
From there, you know that the coefficients of the , , and constant terms are equal on both sides.
The coefficients are both 1, so all set there.
The coefficients of the terms are and , so we know . We can solve that for :
The constants terms are also equal, so we know . We already solved for , so we can say .
Now substitute to find .