5=-4.9x^2+20x+1

Solution for 5=-4.9x^2+20x+1 equation:

5=-4.9x^2+20x+1

We move all terms to the left:

5-(-4.9x^2+20x+1)=0

We get rid of parentheses

4.9x^2-20x-1+5=0

We add all the numbers together, and all the variables

4.9x^2-20x+4=0

a = 4.9; b = -20; c = +4;
Δ = b2-4ac
Δ = -202-4·4.9·4
Δ = 321.6
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-\sqrt{321.6}}{2*4.9}=\frac{20-\sqrt{321.6}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+\sqrt{321.6}}{2*4.9}=\frac{20+\sqrt{321.6}}{9.8}
$