-.25x^2+1.7x+3.5=6

Solution for -.25x^2+1.7x+3.5=6 equation:

-.25x^2+1.7x+3.5=6

We move all terms to the left:

-.25x^2+1.7x+3.5-(6)=0

We add all the numbers together, and all the variables

-0.25x^2+1.7x-2.5=0

a = -0.25; b = 1.7; c = -2.5;
Δ = b2-4ac
Δ = 1.72-4·(-0.25)·(-2.5)
Δ = 0.39
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{-(1.7)-\sqrt{0.39}}{2*-0.25}=\frac{-1.7-\sqrt{0.39}}{-0.5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.7)+\sqrt{0.39}}{2*-0.25}=\frac{-1.7+\sqrt{0.39}}{-0.5}
$