x^2-5x+1+0
x^2-5x+1=0
Are you meant to find x or just factorise? If you are to find x then follow this. \[x^2-5x+1=0\] Use the quadratic formula. \[x=\frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }\]
it says to find all real solutions of the equation by completing the square
ah okay, then don't follow what I did there.
\[x^2-5x=-1\] \[(x-(\frac{ 5 }{ 2 }))=-1+(\frac{ 5 }{ 2 })^{2}\]
To complete the square, move the constant to the other side. \[x^2-ax\] \[(x-\frac{a}{2})^{2}\]
I did a mistake in the second line.
meant to be \[(x-\frac{ 5 }{ 2 })^2=-1+(\frac{ 5 }{ 2 })^2\]
I had it x^2-5x- 25/4= -1 then moved the 25/4 to the other side
That's not how you complete the square.
so I was at x^2-5x= -1 + 6 1/4 which equaled 5 1/4
You're not meant to expand the LHS.
oh ok
\[(x-\frac{ 5 }{ 2 })^2=\frac{ 21 }{ 4 }\] \[x-\frac{ 5 }{ 2 }=\frac{ \pm \sqrt{21} }{ 2 }\]
Move the -5/2 to the RHS.
So then it would be \[x=\frac{ \pm \sqrt{21} }{ 2 }+\frac{ 5 }{ 2 }\] \[x=\frac{ 5\pm \sqrt{21} }{ 2 }\]
thanks for the help
No worries.
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