-2/7u^2+6=0

Solution for -2/7u^2+6=0 equation:

-2/7u^2+6=0


Domain of the equation: 7u^2!=0

u^2!=0/7

u^2!=√0

u!=0

u∈R


We multiply all the terms by the denominator


6*7u^2-2=0

Wy multiply elements

42u^2-2=0

a = 42; b = 0; c = -2;
Δ = b2-4ac
Δ = 02-4·42·(-2)
Δ = 336
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{336}=\sqrt{16*21}=\sqrt{16}*\sqrt{21}=4\sqrt{21}$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{21}}{2*42}=\frac{0-4\sqrt{21}}{84}
=-\frac{4\sqrt{21}}{84}
=-\frac{\sqrt{21}}{21}
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{21}}{2*42}=\frac{0+4\sqrt{21}}{84}
=\frac{4\sqrt{21}}{84}
=\frac{\sqrt{21}}{21}
$