Answer:
x = 1.5 ± √3.75
Step-by-step explanation:
There are several variations of completing the sqaure.
This is the one I use.
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2x² - 6x - 3 = 0
add 3 to both sides
2x² - 6x = 3
the x² coefficient must be 1
so divide both sides by 2
x² - 3x = 1.5
use half the x coefficient (-3/2 = -1.5) as the complete the square term
(x - 1.5)² = 1.5 + (-1.5)²
(x - 1.5)² = 1.5 + 2.25
(x - 1.5)² = 3.75
Take the square root of both sides
x - 1.5 = ± √3.75
add 1.5 to both sides
x = 1.5 ± √3.75
Answer:
x = 1.5 + √3.75 ; x = 1.5 - √3.75
Step-by-step explanation:
2x² - 6x -3 = 0
Add 3 to both sides
2x² - 6x = 3
Divide the entire equation by the coefficient of x²
[tex]\dfrac{2x^{2}}{2}-\dfrac{6x}{2}=\dfrac{3}{2}\\[/tex]
x² - 3x = 1.5
Divide the coefficient of x by 2 and then square it and add to both sides.
3/2 = 1.5
1.5² = 2.25
Add 2.25 to both sides
x² - 3x + 2.25 = 1.5+2.25
(x - 1.5)² = 3.75
Take square root,
x - 1.5 = ±√3.75
x = 1.5 ± √3.75
