-4.9x^2+3.5x+10=9

Solution for -4.9x^2+3.5x+10=9 equation:

-4.9x^2+3.5x+10=9

We move all terms to the left:

-4.9x^2+3.5x+10-(9)=0

We add all the numbers together, and all the variables

-4.9x^2+3.5x+1=0

a = -4.9; b = 3.5; c = +1;
Δ = b2-4ac
Δ = 3.52-4·(-4.9)·1
Δ = 31.85
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{-(3.5)-\sqrt{31.85}}{2*-4.9}=\frac{-3.5-\sqrt{31.85}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3.5)+\sqrt{31.85}}{2*-4.9}=\frac{-3.5+\sqrt{31.85}}{-9.8}
$