7b^2-70b+147=0

Solution for 7b^2-70b+147=0 equation:

7b^2-70b+147=0

a = 7; b = -70; c = +147;
Δ = b2-4ac
Δ = -702-4·7·147
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-70)-28}{2*7}=\frac{42}{14}
=3
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-70)+28}{2*7}=\frac{98}{14}
=7
$