Y=10x2-9x-9

Solution for Y=10x2-9x-9 equation:

=10Y^2-9Y-9

We move all terms to the left:

-(10Y^2-9Y-9)=0

We get rid of parentheses

-10Y^2+9Y+9=0

a = -10; b = 9; c = +9;
Δ = b2-4ac
Δ = 92-4·(-10)·9
Δ = 441
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{441}=21$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-21}{2*-10}=\frac{-30}{-20}
=1+1/2
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+21}{2*-10}=\frac{12}{-20}
=-3/5
$