(5r+3r)(r+1)=O

Solution for (5r+3r)(r+1)=O equation:

(5r+3r)(r+1)=

We move all terms to the left:

(5r+3r)(r+1)-()=0

We add all the numbers together, and all the variables

(+8r)(r+1)-()=0

We add all the numbers together, and all the variables

(+8r)(r+1)=0

We multiply parentheses ..

(+8r^2+8r)=0

We get rid of parentheses

8r^2+8r=0

a = 8; b = 8; c = 0;
Δ = b2-4ac
Δ = 82-4·8·0
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-8}{2*8}=\frac{-16}{16}
=-1
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+8}{2*8}=\frac{0}{16}
=0
$