-2h^2+17h=21

Solution for -2h^2+17h=21 equation:

-2h^2+17h=21

We move all terms to the left:

-2h^2+17h-(21)=0

a = -2; b = 17; c = -21;
Δ = b2-4ac
Δ = 172-4·(-2)·(-21)
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(17)-11}{2*-2}=\frac{-28}{-4}
=+7
$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(17)+11}{2*-2}=\frac{-6}{-4}
=1+1/2
$