A community for students.
Here's the question you clicked on:
 0 viewing
Tabbiejack
 2 years ago
What is the value of c such that: x2 + 14x + c, is a perfectsquare trinomial?<o:p></o:p>
A. 7
B. 98
C. 196
D. 49
Tabbiejack
 2 years ago
What is the value of c such that: x2 + 14x + c, is a perfectsquare trinomial?<o:p></o:p> A. 7 B. 98 C. 196 D. 49

This Question is Closed

ParthKohli
 2 years ago
Best ResponseYou've already chosen the best response.2Observe that a perfect square is in the form \((a + b)^2 = a^2 + 2ab + b^2\). The first term is \(x^2 \) so we get an idea that the perfect square is in the form \((x + b)^2\). Now the middle term is \(2ab\) and here it is \(14x\). We know that \(a = x\) and so \(2x b = 14x \Rightarrow b = 7\). And so we have \((x + 7)^2 = x^2 + 14x + 49\). There's another technique which you can use formally, which is called "Completing the Square". It's just a ripoff of what I did above.

ParthKohli
 2 years ago
Best ResponseYou've already chosen the best response.2That technique says that you get the half of the coefficient of \(x\), and square it to get the last term. So you get the half of \(14\) which is \(7\). The square of that is \(49\).

Jhannybean
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1369717242091:dw

Tabbiejack
 2 years ago
Best ResponseYou've already chosen the best response.0ok it is easier to see it like that

Tabbiejack
 2 years ago
Best ResponseYou've already chosen the best response.0I have another question if you don't mind

Tabbiejack
 2 years ago
Best ResponseYou've already chosen the best response.0Graph the set of points. Which model is most appropriate for the set? ( 1, 20), (0, 10), (1, 5), (2, 2.5)
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.