0=45+10x-4.9x^2

Solution for 0=45+10x-4.9x^2 equation:

0=45+10x-4.9x^2

We move all terms to the left:

0-(45+10x-4.9x^2)=0

We add all the numbers together, and all the variables

-(45+10x-4.9x^2)=0

We get rid of parentheses

4.9x^2-10x-45=0

a = 4.9; b = -10; c = -45;
Δ = b2-4ac
Δ = -102-4·4.9·(-45)
Δ = 982
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:

$\sqrt{\Delta}=\sqrt{982}=\sqrt{1*982}=\sqrt{1}*\sqrt{982}=1\sqrt{982}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-1\sqrt{982}}{2*4.9}=\frac{10-1\sqrt{982}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+1\sqrt{982}}{2*4.9}=\frac{10+1\sqrt{982}}{9.8}
$