175x^2+140x+21=0

Solution for 175x^2+140x+21=0 equation:

175x^2+140x+21=0

a = 175; b = 140; c = +21;
Δ = b2-4ac
Δ = 1402-4·175·21
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(140)-70}{2*175}=\frac{-210}{350}
=-3/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(140)+70}{2*175}=\frac{-70}{350}
=-1/5
$