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 one year 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
 one year 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

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ParthKohli
 one year 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
 one year 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
 one year ago
Best ResponseYou've already chosen the best response.0dw:1369717242091:dw

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

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

Tabbiejack
 one year 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)
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