Y=2(x-9)(x+7)

Solution for Y=2(x-9)(x+7) equation:

=2(Y-9)(Y+7)

We move all terms to the left:

-(2(Y-9)(Y+7))=0

We multiply parentheses ..

-(2(+Y^2+7Y-9Y-63))=0


We calculate terms in parentheses: -(2(+Y^2+7Y-9Y-63)), so:

2(+Y^2+7Y-9Y-63)

We multiply parentheses

2Y^2+14Y-18Y-126

We add all the numbers together, and all the variables

2Y^2-4Y-126

Back to the equation:

-(2Y^2-4Y-126)


We get rid of parentheses

-2Y^2+4Y+126=0

a = -2; b = 4; c = +126;
Δ = b2-4ac
Δ = 42-4·(-2)·126
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-32}{2*-2}=\frac{-36}{-4}
=+9
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+32}{2*-2}=\frac{28}{-4}
=-7
$