(a-10)(a+10)=0a=

Solution for (a-10)(a+10)=0a= equation:

(a-10)(a+10)=0a=

We move all terms to the left:

(a-10)(a+10)-(0a)=0

We add all the numbers together, and all the variables

-1a+(a-10)(a+10)=0

We use the square of the difference formula

a^2-1a-100=0

a = 1; b = -1; c = -100;
Δ = b2-4ac
Δ = -12-4·1·(-100)
Δ = 401
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{401}}{2*1}=\frac{1-\sqrt{401}}{2}
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{401}}{2*1}=\frac{1+\sqrt{401}}{2}
$