7r(2+r)=0

Solution for 7r(2+r)=0 equation:

7r(2+r)=0

We add all the numbers together, and all the variables

7r(r+2)=0

We multiply parentheses

7r^2+14r=0

a = 7; b = 14; c = 0;
Δ = b2-4ac
Δ = 142-4·7·0
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-14}{2*7}=\frac{-28}{14}
=-2
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+14}{2*7}=\frac{0}{14}
=0
$