3=-16(3x)^2+75(3x)

Solution for 3=-16(3x)^2+75(3x) equation:

3=-16(3x)^2+75(3x)

We move all terms to the left:

3-(-16(3x)^2+75(3x))=0

We get rid of parentheses

163x^2-753x+3=0

a = 163; b = -753; c = +3;
Δ = b2-4ac
Δ = -7532-4·163·3
Δ = 565053
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{-(-753)-\sqrt{565053}}{2*163}=\frac{753-\sqrt{565053}}{326}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-753)+\sqrt{565053}}{2*163}=\frac{753+\sqrt{565053}}{326}
$