-4x(4x+10)=-2(8x+20)

Solution for -4x(4x+10)=-2(8x+20) equation:

-4x(4x+10)=-2(8x+20)

We move all terms to the left:

-4x(4x+10)-(-2(8x+20))=0

We multiply parentheses

-16x^2-40x-(-2(8x+20))=0


We calculate terms in parentheses: -(-2(8x+20)), so:

-2(8x+20)

We multiply parentheses

-16x-40

Back to the equation:

-(-16x-40)


We get rid of parentheses

-16x^2-40x+16x+40=0

We add all the numbers together, and all the variables

-16x^2-24x+40=0

a = -16; b = -24; c = +40;
Δ = b2-4ac
Δ = -242-4·(-16)·40
Δ = 3136
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3136}=56$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-24)-56}{2*-16}=\frac{-32}{-32}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-24)+56}{2*-16}=\frac{80}{-32}
=-2+1/2
$