x2-4=4x+8

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Solution for x2-4=4x+8 equation:



x2-4=4x+8
We move all terms to the left:
x2-4-(4x+8)=0
We add all the numbers together, and all the variables
x^2-(4x+8)-4=0
We get rid of parentheses
x^2-4x-8-4=0
We add all the numbers together, and all the variables
x^2-4x-12=0
a = 1; b = -4; c = -12;
Δ = b2-4ac
Δ = -42-4·1·(-12)
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-8}{2*1}=\frac{-4}{2} =-2 $
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+8}{2*1}=\frac{12}{2} =6 $

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