<p>I was doing some practice problems and this one stumped me:</p>
<p>In the equation below, k and m are constants. If the equation is true for all values of x, what is the value of m?</p>
<p>(x-8)(x-k)=x^2-5kx+m</p>
<p>A) 8 B) 16 C) 24 D) 32 E) 40</p>
<p>Please explain how to get the correct answer (B). Thanks for your help.</p>
<p>First, expand (x-8)(x-k). You’ll get x^2-8x-kx+8k. This is equal to x^2-5kx+m. Therefore, -8-k=-5k and then we get k=2. Also, 8k=m. Inserting the value we got for k, we get the value of m to be 16. I do hope that I made sense.</p>
<p>I get it now. Thanks for the explanation.</p>
<p>Your Welcome</p>