y^2-6.5y+10.5=0

Solution for y^2-6.5y+10.5=0 equation:

y^2-6.5y+10.5=0

a = 1; b = -6.5; c = +10.5;
Δ = b2-4ac
Δ = -6.52-4·1·10.5
Δ = 0.25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6.5)-\sqrt{0.25}}{2*1}=\frac{6.5-\sqrt{0.25}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6.5)+\sqrt{0.25}}{2*1}=\frac{6.5+\sqrt{0.25}}{2}
$