7d^2-10d=0

Solution for 7d^2-10d=0 equation:

7d^2-10d=0

a = 7; b = -10; c = 0;
Δ = b2-4ac
Δ = -102-4·7·0
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-10}{2*7}=\frac{0}{14}
=0
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+10}{2*7}=\frac{20}{14}
=1+3/7
$