<p>If k and h are constants and x^2 + kx + 7 is equivalent to (x+1)(x+h), what is the value of k?
a. 0
b. 1
c. 7
d. 8
e. Not enough info.
Answer is d.
Explain please in simple words =D</p>
<p>If you factor x^2 + kx + 7 with (x+1) as one of the roots, then it must be (x+7) for the second root, as 7 is the third term.</p>
<p>Once you know this, you know that the coefficient for the second term, namely k, must be the two numbers from the roots (still in parentheses) multiplied by each other. Since the roots are (x+1)(x+7), k must equal 8.</p>
<p>Hope this makes sense!</p>
<p>expand: x^2 + kx + 7 = (x+1)(x+h) = x^2 + (h+1)x + h
=> kx + 7 = (h+1)x + h
=> h = 7, k = h+1 = 8
answer D.</p>
<p>Like what pneumoconiosis said, in my own words:</p>
<p>x^2 + kx + 7, assuming (x+1) is a root, factors into (x+1)(x+7)</p>
<p>FOIL (x+1)(x+7)</p>
<p>= x^2 + 7x + 1x + 7
= x^2 + 8x + 7</p>
<p>Sorry, I meant “add” for the second coefficient, not “multiply.”</p>
<p>for any quadratic equation: ax^2+bx+c=0… if D1 and D2 are the roots of the equation then,</p>
<p>D1 + D2 = -b/(2*a) and D1 * D2= c/a</p>
<p>Now as ur question says:</p>
<p>x^2 + kx + 7 is equivalent to (x+1)(x+h), that means -1 and -h are the roots of the given quadratic equation…</p>
<p>Now use the above facts to solve it and save some time…</p>