D(x)=3/5x+5

Solution for D(x)=3/5x+5 equation:

(D)=3/5D+5

We move all terms to the left:

(D)-(3/5D+5)=0


Domain of the equation: 5D+5)!=0

D∈R


We get rid of parentheses

D-3/5D-5=0

We multiply all the terms by the denominator


D*5D-5*5D-3=0

Wy multiply elements

5D^2-25D-3=0

a = 5; b = -25; c = -3;
Δ = b2-4ac
Δ = -252-4·5·(-3)
Δ = 685
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$D_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$D_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$D_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-25)-\sqrt{685}}{2*5}=\frac{25-\sqrt{685}}{10}
$
$D_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-25)+\sqrt{685}}{2*5}=\frac{25+\sqrt{685}}{10}
$