Y=7x(x-8)

Solution for Y=7x(x-8) equation:

=7Y(Y-8)

We move all terms to the left:

-(7Y(Y-8))=0


We calculate terms in parentheses: -(7Y(Y-8)), so:

7Y(Y-8)

We multiply parentheses

7Y^2-56Y

Back to the equation:

-(7Y^2-56Y)


We get rid of parentheses

-7Y^2+56Y=0

a = -7; b = 56; c = 0;
Δ = b2-4ac
Δ = 562-4·(-7)·0
Δ = 3136
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3136}=56$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(56)-56}{2*-7}=\frac{-112}{-14}
=+8
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(56)+56}{2*-7}=\frac{0}{-14}
=0
$