0=70n+-1n2

Solution for 0=70n+-1n2 equation:

0=70n+-1n^2

We move all terms to the left:

0-(70n+-1n^2)=0

We add all the numbers together, and all the variables

-(70n+-1n^2)=0

We use the square of the difference formula

-(70n-1n^2)=0

We get rid of parentheses

1n^2-70n=0

We add all the numbers together, and all the variables

n^2-70n=0

a = 1; b = -70; c = 0;
Δ = b2-4ac
Δ = -702-4·1·0
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-70)-70}{2*1}=\frac{0}{2}
=0
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-70)+70}{2*1}=\frac{140}{2}
=70
$