8=-4.9x^2+16x+12

Solution for 8=-4.9x^2+16x+12 equation:

8=-4.9x^2+16x+12

We move all terms to the left:

8-(-4.9x^2+16x+12)=0

We get rid of parentheses

4.9x^2-16x-12+8=0

We add all the numbers together, and all the variables

4.9x^2-16x-4=0

a = 4.9; b = -16; c = -4;
Δ = b2-4ac
Δ = -162-4·4.9·(-4)
Δ = 334.4
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{-(-16)-\sqrt{334.4}}{2*4.9}=\frac{16-\sqrt{334.4}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+\sqrt{334.4}}{2*4.9}=\frac{16+\sqrt{334.4}}{9.8}
$