30=-16x^2+8x+48

Solution for 30=-16x^2+8x+48 equation:

30=-16x^2+8x+48

We move all terms to the left:

30-(-16x^2+8x+48)=0

We get rid of parentheses

16x^2-8x-48+30=0

We add all the numbers together, and all the variables

16x^2-8x-18=0

a = 16; b = -8; c = -18;
Δ = b2-4ac
Δ = -82-4·16·(-18)
Δ = 1216
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:

$\sqrt{\Delta}=\sqrt{1216}=\sqrt{64*19}=\sqrt{64}*\sqrt{19}=8\sqrt{19}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-8\sqrt{19}}{2*16}=\frac{8-8\sqrt{19}}{32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+8\sqrt{19}}{2*16}=\frac{8+8\sqrt{19}}{32}
$