0=-1.4x^2+14x

Solution for 0=-1.4x^2+14x equation:

0=-1.4x^2+14x

We move all terms to the left:

0-(-1.4x^2+14x)=0

We add all the numbers together, and all the variables

-(-1.4x^2+14x)=0

We get rid of parentheses

1.4x^2-14x=0

a = 1.4; b = -14; c = 0;
Δ = b2-4ac
Δ = -142-4·1.4·0
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-14}{2*1.4}=\frac{0}{2.8}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+14}{2*1.4}=\frac{28}{2.8}
=10
$