The exact solutions to the quadratic equation 0 = 6x2 - 9x - 3 can be written in the form x=p+q√r. What is the value of p+q+r?
4 years ago
Some of the info you tried to copy didn't come through so I'm going to take a guess at what the question is. Feel free to ask again if I'm wrong!
0 = 6x2 - 9x - 3
0 = 3*(2x2 - 3x - 1)
This trinomial (2x2 - 3x - 1) cannot be factored further, so we use the quadratic equation.
This gives us the roots
x = 3/4 + sqrt(17/16)
x = 3/4 - sqrt(17/16)
If you don't want to use the quadratic formula, you can complete the square:
2x2 - 3x - 1 = 0 - divide by 2
x2 - 3x/2 - 1/2 = 0 - add 1/2 to both sides
x2 - 3x/2 = 1/2
divide B (3/2) by two, square it, and add to both sides C = (3/2 * 1/2)2 = 9/16
Note, part of our root is going to be 3/2*1/2 =(3/4)
x2 - 3x/2 + 9/16 = 1/2 + 9/16
(x - 3/4)2 = 17/16
The square has a positive AND negative root ( sqrt(1) is both +1 and -1)
x - 3/4 = sqrt(17/16)
- (x - 3/4) = sqrt(17/16)
Solving for x, we get
Don't forget to put the two solutions back into your original equation to make sure both = 0!
4 years ago
Answered By Emily D
Some of the info you tried to copy didn't come through so I'm going to take a guess at what the question is. Feel free to ask again if I'm wrong!
0 = 6x2 - 9x - 3
0 = 3*(2x2 - 3x - 1)
This trinomial (2x2 - 3x - 1) cannot be factored further, so we use the quadratic equation.
This gives us the roots
x = 3/4 + sqrt(17/16)
x = 3/4 - sqrt(17/16)
4 years ago
Answered By Emily D
If you don't want to use the quadratic formula, you can complete the square:
2x2 - 3x - 1 = 0 - divide by 2
x2 - 3x/2 - 1/2 = 0 - add 1/2 to both sides
x2 - 3x/2 = 1/2
divide B (3/2) by two, square it, and add to both sides C = (3/2 * 1/2)2 = 9/16
Note, part of our root is going to be 3/2*1/2 =(3/4)
x2 - 3x/2 + 9/16 = 1/2 + 9/16
(x - 3/4)2 = 17/16
The square has a positive AND negative root ( sqrt(1) is both +1 and -1)
x - 3/4 = sqrt(17/16)
- (x - 3/4) = sqrt(17/16)
Solving for x, we get
x = 3/4 + sqrt(17/16)
x = 3/4 - sqrt(17/16)
4 years ago
Answered By Emily D
Don't forget to put the two solutions back into your original equation to make sure both = 0!