Question

Which of the following values of k makes the polynomial a perfect square?

x2 + 11x + k

a. 2/121
b.121
c.121/4
d.121/2

Answer 1

Perfect square: \((a+b)^2 = a^2+2ab+b^2\)
Now, you have x^2 + 11x + k
k is b^2 in the general form and a = x.
Consider the middle term,
2ab = 11x -(1)
Put a=x and \(b=\sqrt{k}\) into (1)
2(x)(\(\sqrt{k}\)) = 11x
\(2\sqrt{k}\)=11
Now, solve k and get your answer!

Answer 2

Im so confused..

Answer 3

I need to have this done by 4:30 & im no where near done

Answer 4

Which part are you confused at?

Answer 5

on everything.

Answer 6

Do you know the identity of perfect square?

Answer 7

no not at all. Im returning my friend a favor by doing his work & im trying to impress him

Answer 8

But you are like.... asking us to do some work for you to impress him....

Perfect square expansion: \((a\pm b)^2 = a^2 \pm 2ab + b^2\)
You can get this identity by expanding the left side.
Try to expand (a+b)(a+b). What do you get?

Answer 9

\[(x+k)^2=x^2+2(k)(x)+k^2\]\[x^2+2kx+k^2=x^2+11x+k\]

Answer 10

never mind i found the asnwer