+0  
 
0
152
2
avatar

Use the completing the square method to solve the following. Round the solutions to the nearest tenth place.

 

1. n= 18n + 40

 

 

 

2. 6x2 - 48 = -12x 

Guest Mar 16, 2018
 #1
avatar+13014 
+2

1)  n^2 -18n  = 40      take 1/2 of the 'n' coefficient, square it , then add it ro both the sides of the equation

 

n^2 -18n + 81 = 40  + 81

(n-9)^2     = 121                        Now take sqrt of both sides

(n-9) = +- 11

n=20  or  -2

ElectricPavlov  Mar 16, 2018
 #2
avatar+13014 
+1

2) similar here

6x^2 +12x = 48

 

BUT you need to have x^2 coefficient = 1    so divide through by 6

x^2 + 2x = 8      Now 'complete the square' again

 

x^2 + 2x +1 = 8+1

(x+1)^2  =  9

x + 1    = +- 9

x =8 or -10

ElectricPavlov  Mar 16, 2018

29 Online Users

avatar
avatar
avatar
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.