3.9x^2-25=0

Solution for 3.9x^2-25=0 equation:

3.9x^2-25=0

a = 3.9; b = 0; c = -25;
Δ = b2-4ac
Δ = 02-4·3.9·(-25)
Δ = 390
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{390}}{2*3.9}=\frac{0-\sqrt{390}}{7.8}
=-\frac{\sqrt{}}{7.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{390}}{2*3.9}=\frac{0+\sqrt{390}}{7.8}
=\frac{\sqrt{}}{7.8}
$