(4-k)(1/5)=0.25

Solution for (4-k)(1/5)=0.25 equation:

(4-k)(1/5)=0.25

We move all terms to the left:

(4-k)(1/5)-(0.25)=0

We add all the numbers together, and all the variables

(-1k+4)(+1/5)-(0.25)=0

We add all the numbers together, and all the variables

(-1k+4)(+1/5)-0.25=0

We multiply parentheses ..

(-1k^2+4*1/5)-0.25=0

We multiply all the terms by the denominator


(-1k^2+4*1-(0.25)*5)=0


We calculate terms in parentheses: +(-1k^2+4*1-(0.25)*5), so:

-1k^2+4*1-(0.25)*5

We add all the numbers together, and all the variables

-1k^2+2.75

Back to the equation:

+(-1k^2+2.75)


We get rid of parentheses

-1k^2+2.75=0

a = -1; b = 0; c = +2.75;
Δ = b2-4ac
Δ = 02-4·(-1)·2.75
Δ = 11
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{11}}{2*-1}=\frac{0-\sqrt{11}}{-2}
=-\frac{\sqrt{}}{-2}
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{11}}{2*-1}=\frac{0+\sqrt{11}}{-2}
=\frac{\sqrt{}}{-2}
$