0=-0.005x^2+0.7x+3.5

Solution for 0=-0.005x^2+0.7x+3.5 equation:

0=-0.005x^2+0.7x+3.5

We move all terms to the left:

0-(-0.005x^2+0.7x+3.5)=0

We add all the numbers together, and all the variables

-(-0.005x^2+0.7x+3.5)=0

We get rid of parentheses

0.005x^2-0.7x-3.5=0

a = 0.005; b = -0.7; c = -3.5;
Δ = b2-4ac
Δ = -0.72-4·0.005·(-3.5)
Δ = 0.56
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{-(-0.7)-\sqrt{0.56}}{2*0.005}=\frac{0.7-\sqrt{0.56}}{0.01}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.7)+\sqrt{0.56}}{2*0.005}=\frac{0.7+\sqrt{0.56}}{0.01}
$