SOLUTION: I am taking college Algebra for the first time and since math has always been my worst subject I need all the help I can get. I thank you in advance for all your help. Using the

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: I am taking college Algebra for the first time and since math has always been my worst subject I need all the help I can get. I thank you in advance for all your help. Using the      Log On


   

Question 24374: I am taking college Algebra for the first time and since math has always been my worst subject I need all the help I can get. I thank you in advance for all your help.
Using the quadratic equation x squared -4x-5=0, perform the following tasks:
Solve by factoring: (I got x=5 or x=1)
Solve by completing the square:
Solve by using the quadratic formula:
I submitted this before but never recieved an answer back. I think I may have submitted it wrong. Again thank you for your help. BTW this is all part of the first question.
Answer by yhtong(11) About Me  (Show Source):
You can put this solution on YOUR website!
Ok, heres what you do. Your questions is x²-4x-5=0
By factorizing
x²-4x-5=0
(x-5)(x+1)=0
and there would be two answers
1) x-5=0
x=5
2) x+3=0
x=-1
By completing of square
x²-4x-5=0
x²-4x =+5
x²-4x+(4/2)²=5+(4/2)²
x²-4x+(2)² =5+(2)²
(x-2)(x-2) =5+4
(x-2)² =9
x-2 = +or- (square root of 9)
x-2 =+or-(3)
and there will be 2 answers as well
1)x=3+2
x=5
2)x=-3+2
x=-1
By formula.
Formula of to solve the above equation is

x+=+%28--4+%2B-sqrt%28+-4%5E2-4%2A1%2A-5+%29%29%2F%282%2A1%29+
=x+=+%28%2B4+%2B-sqrt%28+16%2B20%29%29%2F%282%29+
=x+=+%284+%2B-sqrt%28+36+%29%29%2F%282%29+
=(4+or-6)/2
this also got 2 answers as well
1)x=(4+6)/2
x=10/2
x=5
2)x=(4-6)/2
x=-2/2
x=-1
therefore your answers are 5 or -1
(dont be surprised that i am a secondary pure science stream student)
yh_tong