Hi
Can anyone tell me if this is correct
X Sq - 4x - 16 = 0
using
X = -b + Sqrt b sqrd - 4ac / 2a
a =1, b = -4 , C = -16
x = -(-4) Sqrt (-4)sq - 4 x 1 x -16 / 2 x 1
= 4 + - Sqrt 80
= 9 + or minus 8.944/2
+ = 4 + 8.944 = 12.944/2
= 6.472
- = 4 - 8.944 = - 4.944/2
= - 2.472
I apologise in advance for the layout..but know people here are helpful and understanding ..
If this is wrong please tell me where I have gone wrong..thanks :-)
Your answers are correct but I don't like the way you typed your solution.
I am sure on paper it would look better.
first of all use brackets to avoid problems with order of operation.
Your first line should have looked like this
x = (-(-4) Sqrt (-4)sq - 4 x 1 x -16 )/ 2 x 1 , the way you had it only the square root term would have been divided by 2
in the next line you had
= 4 + - Sqrt 80
you dropped the denominator, but then somehow it must have come back in the next few calculations.
When you use an "=" sign, you are saying,"What I am about to write down next is exactly equal to what I had before".
Your two lines are not "equal"
How about this:
(4 + - Sqrt 80)/2
= 6.472 or - 2.472
btw,
(4 + - Sqrt 80)/2
=(4 ±4√5)/2
= 2 ±2√5 , this would be an acceptable answer.
Thank you for your time and expertise and it does look better on paper ...:-)
than the way I typed it here
Thanks again !!!!
Hello! It seems like you are trying to solve a quadratic equation of the form X^2 - 4X - 16 = 0 using the quadratic formula.
The quadratic formula states that for an equation of the form AX^2 + BX + C = 0, the solutions for X can be found using the formula:
X = (-B ± √(B^2 - 4AC)) / (2A)
Now, let's solve the equation step by step:
Given: X^2 - 4X - 16 = 0
Comparing with the standard form AX^2 + BX + C = 0, we have:
A = 1, B = -4, C = -16
Plugging these values into the quadratic formula, we get:
X = (-( -4) ± √((-4)^2 - 4(1)(-16))) / (2(1))
Simplifying further:
X = (4 ± √(16 + 64)) / 2
X = (4 ± √(80)) / 2
Now, you correctly calculated the square root of 80 as √80 = 8.944.
Let's continue with the calculations:
For the "+" solution:
X = (4 + 8.944) / 2
X = 12.944 / 2
X = 6.472
For the "-" solution:
X = (4 - 8.944) / 2
X = -4.944 / 2
X = -2.472
Therefore, the solutions to the equation X^2 - 4X - 16 = 0 are X = 6.472 and X = -2.472.
I hope this explanation helps! Let me know if you have any more questions.