28x^2+10x-2=0

Solution for 28x^2+10x-2=0 equation:

28x^2+10x-2=0

a = 28; b = 10; c = -2;
Δ = b2-4ac
Δ = 102-4·28·(-2)
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-18}{2*28}=\frac{-28}{56}
=-1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+18}{2*28}=\frac{8}{56}
=1/7
$