12=(x+70)x0,05

Solution for 12=(x+70)x0,05 equation:

12=(x+70)x0.05

We move all terms to the left:

12-((x+70)x0.05)=0


We calculate terms in parentheses: -((x+70)x0.05), so:

(x+70)x0.05

We multiply parentheses

x^2+70x

Back to the equation:

-(x^2+70x)


We get rid of parentheses

-x^2-70x+12=0

We add all the numbers together, and all the variables

-1x^2-70x+12=0

a = -1; b = -70; c = +12;
Δ = b2-4ac
Δ = -702-4·(-1)·12
Δ = 4948
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4948}=\sqrt{4*1237}=\sqrt{4}*\sqrt{1237}=2\sqrt{1237}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-70)-2\sqrt{1237}}{2*-1}=\frac{70-2\sqrt{1237}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-70)+2\sqrt{1237}}{2*-1}=\frac{70+2\sqrt{1237}}{-2}
$