# complet the square

• June 3rd 2010, 06:19 PM
bball20
complet the square
Solve by completing the square:

x^2 + 7/2x =7 (7/2x is a fraction)
• June 3rd 2010, 06:25 PM
tharris
To ind the "magic number" that will complete the square - use the formula (b/2)^2. Then add this "magic number" to both sides of the equation. After doing this, you will be able to factor the left hand side into a perfect square trinomial. Then simply take the square root of both sides and continue to solve for x. To divide a fraction by two remember to invert and multiply, then simply square the numerator (top) and the denominator (bottom). If you need more help. Let me know.(Rofl)
• June 3rd 2010, 06:32 PM
bball20
sorry but I am lost? I have no idea what you just said...
• June 3rd 2010, 08:02 PM
harish21
Quote:

Originally Posted by bball20
Solve by completing the square:

x^2 + 7/2x =7 (7/2x is a fraction)

$x^2+ 2 \times \frac{1}{2}\times \frac{7}{2}x +\left(\frac{7}{4}\right)^2 - {\left(\frac{7}{4}\right)}^2 = 7$

${\left( x+\frac{7}{4}\right)}^2 = 7+{\left(\frac{7}{4}\right)}^2$
• June 4th 2010, 05:06 AM
HallsofIvy
Compare: $(x+ a)^2=$
$x^2+ 2ax+ a^2$ and
$x^2+ (7/2)x+ ?$

With 2a= 7/2, what is a? And then what is $a^2$?