4x(4x-14)=0

Solution for 4x(4x-14)=0 equation:

4x(4x-14)=0

We multiply parentheses

16x^2-56x=0

a = 16; b = -56; c = 0;
Δ = b2-4ac
Δ = -562-4·16·0
Δ = 3136
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3136}=56$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-56)-56}{2*16}=\frac{0}{32}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-56)+56}{2*16}=\frac{112}{32}
=3+1/2
$