Y=7x^2-45x-28

Solution for Y=7x^2-45x-28 equation:

=7Y^2-45Y-28

We move all terms to the left:

-(7Y^2-45Y-28)=0

We get rid of parentheses

-7Y^2+45Y+28=0

a = -7; b = 45; c = +28;
Δ = b2-4ac
Δ = 452-4·(-7)·28
Δ = 2809
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2809}=53$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(45)-53}{2*-7}=\frac{-98}{-14}
=+7
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(45)+53}{2*-7}=\frac{8}{-14}
=-4/7
$