-12x+4.9x^2-17=0

Solution for -12x+4.9x^2-17=0 equation:

-12x+4.9x^2-17=0

a = 4.9; b = -12; c = -17;
Δ = b2-4ac
Δ = -122-4·4.9·(-17)
Δ = 477.2
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{-(-12)-\sqrt{477.2}}{2*4.9}=\frac{12-\sqrt{477.2}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+\sqrt{477.2}}{2*4.9}=\frac{12+\sqrt{477.2}}{9.8}
$