(-4x^2)+12x-1.4375=0

Solution for (-4x^2)+12x-1.4375=0 equation:

(-4x^2)+12x-1.4375=0

We get rid of parentheses

-4x^2+12x-1.4375=0

a = -4; b = 12; c = -1.4375;
Δ = b2-4ac
Δ = 122-4·(-4)·(-1.4375)
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(12)-11}{2*-4}=\frac{-23}{-8}
=2+7/8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(12)+11}{2*-4}=\frac{-1}{-8}
=1/8
$