Solve the following quadratic equation:
1.). X² + 7 = 3x²


Please help me po... I need the answer as soon as possible :(


Sagot :

Okay, gagawin ko siyang simple lang

So ang quadratic equation is in the form:
[tex]a x^{2} +bx+c=0[/tex]
where [tex]a \neq 0[/tex]

[tex]x^2+7=3x^2[/tex]
subtract [tex] x^{2} [/tex] from both sides
[tex]7=2x^2[/tex]
Subtract 7 from both sides 
[tex]0=2x^2-7[/tex]

The quadratic formula is:
[tex] \frac{-b+ \sqrt{b^2-4ac} }{2a} [/tex] and [tex] \frac{-b- \sqrt{b^2-4ac} }{2a} [/tex]
Since x has two roots

So we plug in the values:
[tex] \frac{-(0)+ \sqrt{0-(4)(2)(-7)} }{2(2)} \\ \frac{ \sqrt{56} }{4} \\ \frac{2 \sqrt{14} }{4} \\ \frac{ \sqrt{14} }{2} [/tex]

The other root is the negative value of this which is [tex]- \frac{ \sqrt{14} }{2} [/tex]

The values of x are [tex] \frac{ \sqrt{14}}{2} [/tex] and [tex]- \frac{ \sqrt{14} }{2} [/tex]