Answer:
x=7,−7
Step-by-step explanation:
In order to find the value of x in this quadratic equation we first need to make the equation equal 0 by getting rid of the 140. We do this by subtracting 140 on each side.
3x² - 7 = 140
3x² - 147 = 0
Now we solve as a regular quadratic formula
x= [tex]x = \frac{-(0) +- \sqrt{0^{2} - 4(3)(-147) } }{2(3)}[/tex]
[tex]x = \frac{0 +- \sqrt{1764} }{6}[/tex]
x=7,−7