-0.04x^2+0.7x+2.25=0

Solution for -0.04x^2+0.7x+2.25=0 equation:

-0.04x^2+0.7x+2.25=0

a = -0.04; b = 0.7; c = +2.25;
Δ = b2-4ac
Δ = 0.72-4·(-0.04)·2.25
Δ = 0.85
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{-(0.7)-\sqrt{0.85}}{2*-0.04}=\frac{-0.7-\sqrt{0.85}}{-0.08}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.7)+\sqrt{0.85}}{2*-0.04}=\frac{-0.7+\sqrt{0.85}}{-0.08}
$