Y=10x^2-21x+8

Solution for Y=10x^2-21x+8 equation:

=10Y^2-21Y+8

We move all terms to the left:

-(10Y^2-21Y+8)=0

We get rid of parentheses

-10Y^2+21Y-8=0

a = -10; b = 21; c = -8;
Δ = b2-4ac
Δ = 212-4·(-10)·(-8)
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(21)-11}{2*-10}=\frac{-32}{-20}
=1+3/5
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21)+11}{2*-10}=\frac{-10}{-20}
=1/2
$