SOLUTION: I need help figuring out how to do these quadratic formulas. Any help would be great, thanks so much!!!!!!! Solve using the quadratic formula: x2 – 5x – 1 = -7

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: I need help figuring out how to do these quadratic formulas. Any help would be great, thanks so much!!!!!!! Solve using the quadratic formula: x2 – 5x – 1 = -7       Log On


   

Question 81506: I need help figuring out how to do these quadratic formulas. Any help would be great, thanks so much!!!!!!!



Solve using the quadratic formula:
x2 – 5x – 1 = -7
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!


       
           xē – 5x – 1 = -7

Get 0 on the right by adding 7 from both sides


           xē - 5x + 6 = 0

Use the quadratic formula:
                  ______ 
            -b ą Öbē-4ac
        x = —————————————
                2a 

where a = 1; b = -5; c = +6

                      _____________
             -(-5) ą Ö(-5)ē-4(1)(6)
        x = ————————————————————————
                     2(1) 
                  _____ 
             5 ą Ö25-24
        x = —————————————
                  2

                  _ 
             5 ą Ö1
        x = ——————————
                 2 

                    
             5 ą 1
        x = ———————
               2 

                       
Using the +,

             5 + 1
        x = ———————
               2 

             6
        x = ———
             2 
       
        x = 3

                        
Using the -, 

             5 - 1
        x = ———————
               2 

             4
        x = ———
             2 

         x = 2
    
Edwin