Arveidn
Answered

IDNStudy.com, ang iyong destinasyon para sa mga maaasahang sagot. Makakuha ng mga kumpletong sagot sa lahat ng iyong mga tanong mula sa aming network ng mga eksperto.

Solving quadratic equation by completing the square. Help me please
1. 5p^2 + 2p -9=0
2. 2y^2 -3y-8=0


Sagot :

Solving Quadratic Equation by Completing the Square:
ALWAYS REMEMBER the standard form of a Quadratic Equation is Ax2 + Bx + C = 0.   1.       5p+ 2p – 9 = 0  
First ALWAYS make your A=1. In this case, you need to DIVIDE the whole equation by 5.  

So, we can have:    
(5p+ 2p – 9)/5 = 0/5    
p2 + 2/5 p – 9/5 = 0
   
p2 + 2/5 p = 9/5
 

Next get (B/2)2 and ADD it to the terms on the LEFT and RIGHT side of the equation.  
(B/2)2  =   {(2/5)(1/2)}2             
           = (1/5)2
 
(B/2)2  = 1/25
 

p2 + 2/5 p + 1/25 = 9/5 + 1/25
 

This time we have completed the square (the Left side of the equation is a perfect square; it can be factored completely)   And we will have:  

(p + 1/5)2  =  (45+1)/25
 
(p + 1/5)2  =  46/25  

Then take the square root of both sides of the equation for us to get the roots. We have:  

p +1/ 5 = √(46/25)
p + 1/5  = (√46)/5  
p = +/-  (√46)/5  - 1/5  

So you now have the roots that will satisfy your equation:  

P1 = (√46)/5  - 1/5                                              p2 = - (√46)/5  - 1/5                        
     P1   = {(√46)-1} / 5       ANSWER                   p2 = - {(√46)-1} / 5  ANSWER
View image Rider21