0=-4.9x^2+28x+2

Solution for 0=-4.9x^2+28x+2 equation:

0=-4.9x^2+28x+2

We move all terms to the left:

0-(-4.9x^2+28x+2)=0

We add all the numbers together, and all the variables

-(-4.9x^2+28x+2)=0

We get rid of parentheses

4.9x^2-28x-2=0

a = 4.9; b = -28; c = -2;
Δ = b2-4ac
Δ = -282-4·4.9·(-2)
Δ = 823.2
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{-(-28)-\sqrt{823.2}}{2*4.9}=\frac{28-\sqrt{823.2}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+\sqrt{823.2}}{2*4.9}=\frac{28+\sqrt{823.2}}{9.8}
$