+0  
 
0
79
1
avatar+604 

The quadratic $x^2-20x+36$ can be written in the form $(x+b)^2+c$, where $b$ and $c$ are constants. What is $b+c$?

gueesstt  May 6, 2018
 #1
avatar+19604 
+1

The quadratic $x^2-20x+36$ can be written in the form $(x+b)^2+c$, where $b$ and $c$ are constants.

What is $b+c$?

 

\(\begin{array}{|rclrcl|} \hline x^2+20x+36 &=& (x+b)^2+c \\ &=& x^2+\underbrace{2b}_{=20}\cdot x + \underbrace{(b^2+c)}_{=36} \\ \hline 2b &=& 20 & b^2+c &=& 36 \\ \mathbf{b} &\mathbf{=}& \mathbf{10} & 10^2+c &=& 36 \\ &&& c &=& 36 - 100 \\ &&& \mathbf{c} &\mathbf{=}& \mathbf{-64} \\\\ b+c &=& 10-64 \\ \mathbf{b+c} &\mathbf{=}& \mathbf{-54}\\ \hline \end{array}\)

 

laugh

heureka  May 7, 2018

10 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.