k=8/9k

Solution for k=8/9k equation:

k=8/9k

We move all terms to the left:

k-(8/9k)=0


Domain of the equation: 9k)!=0

k!=0/1

k!=0

k∈R


We add all the numbers together, and all the variables

k-(+8/9k)=0

We get rid of parentheses

k-8/9k=0

We multiply all the terms by the denominator


k*9k-8=0

Wy multiply elements

9k^2-8=0

a = 9; b = 0; c = -8;
Δ = b2-4ac
Δ = 02-4·9·(-8)
Δ = 288
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{288}=\sqrt{144*2}=\sqrt{144}*\sqrt{2}=12\sqrt{2}$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12\sqrt{2}}{2*9}=\frac{0-12\sqrt{2}}{18}
=-\frac{12\sqrt{2}}{18}
=-\frac{2\sqrt{2}}{3}
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12\sqrt{2}}{2*9}=\frac{0+12\sqrt{2}}{18}
=\frac{12\sqrt{2}}{18}
=\frac{2\sqrt{2}}{3}
$