5a^2-16a-45=0

Solution for 5a^2-16a-45=0 equation:

5a^2-16a-45=0

a = 5; b = -16; c = -45;
Δ = b2-4ac
Δ = -162-4·5·(-45)
Δ = 1156
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1156}=34$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-34}{2*5}=\frac{-18}{10}
=-1+4/5
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+34}{2*5}=\frac{50}{10}
=5
$