30=-4.9x^2+27x+2.4

Solution for 30=-4.9x^2+27x+2.4 equation:

30=-4.9x^2+27x+2.4

We move all terms to the left:

30-(-4.9x^2+27x+2.4)=0

We get rid of parentheses

4.9x^2-27x-2.4+30=0

We add all the numbers together, and all the variables

4.9x^2-27x+27.6=0

a = 4.9; b = -27; c = +27.6;
Δ = b2-4ac
Δ = -272-4·4.9·27.6
Δ = 188.04
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{-(-27)-\sqrt{188.04}}{2*4.9}=\frac{27-\sqrt{188.04}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-27)+\sqrt{188.04}}{2*4.9}=\frac{27+\sqrt{188.04}}{9.8}
$